Am I obligated to pay the rent in this case (read on)?

I just moved into a new apartment less than two weeks ago. When I left my last apartment, my landlord said I was financially obligated to still pay the rent as well as lose my deposit since I would be breaking my lease when I left.
I've lived at that place since Oct of '02. Since then, I've went to the office to re-sign the original lease next to a handwritten line stating that the lease would be extended for another year every year up until Oct of '06. Thing is, last August ('06) the original landlord sold the property to new owners. And when last October arrived, I was NEVER called in to re-sign the lease for another year.
When I left my old place I stopped in to talk to the manager, it was then she mentioned that I was obligated to pay to pay until October of this year, but since she found someone to move in in August I was off the hook from then on. She said I was stilll obligated to pay for July, though. So this weekend I dropped off a check because she said if I didn't pay, they would come after me. I didn't want my credit affected, so I payed for July.
At the time I talked to the manager, I requested a copy of my lease. She gave it to me, and it had my signatures for '02 to '03, '03 to '04, '04 to '05, and '05 to '06. Remember I said I didn't go in and sign anything for '06 to '07.
Here's the thing: on the handwritten part for '05 to '06, it was obviously altered and a 6 was written over the 5, and a 7 was written over the 6 so it appeared that I signed for '06 to '07. So if this were actually the case, it would leave a gap in the timeline for '05 to '06 where I didn't sign.
Is this a valid practice? Am I obligated to this lease even though I didn't actually sign it for '06 to '07, but someone altered it so it looks like I did? They didn't even use white-out over the old numbers so its obvious that it was altered and the old numbers can be clearly seen.

Yes I do have a copy of the lease, and I only noticed the altered numbers yesterday, after I dropped off the check for July. The lease says nothing about what would happen if I didn't sign for another year in terms of month-to-month or if the lease automatically rolls over to another year.

I sounds like to me that the landlord who sold the property deliberately rolled your lease forward to create value in the sale. Do you have copies of the leases you signed? ALWAYS get a copy of anything you sign. You should not be obligated to pay. If they take you to court, which they probably won't, its just a scared tactic we landlords use.

I suggest you forget it. If you have a copy of the altered lease, write to the Apartment Association and enclose a copy of the altered lease.
Sounds fraudulent.

The altered numbers is an important factor, but a key bit of information is what does the lease say about if you don't sign? Most leases will have one of two clauses in it that covers this.

The first type of clause says that at the end of the lease your time reverts to a month-to-month rental, so your tenancy can be terminated with 30 days notice.

The second type says that if no action is taken on a lease, then at the end of the lease period the lease extends for an additional year. (Or in a few cases, 6 months)

A very few leases say nothing about this.

If your lease either says nothing about the subject, or says it reverts to a month-to-month, then you have a case, although it will be difficult to proove the fraud in court.

If it is revert to another year, it doesn't matter.

you never agreed to a lease that obligated you to pay through October 07 so you are not obligated to pay for anything past October 06, I would contact an attorney to get back your money for any month that you weren't living there plus your deposit, what they did (changing the document after you signed) is fraudulent and they could get in big trouble for it, if you have an attoryney contact them they will probably refund your money without having to go to court because they will want to avoid being tried for fraud.

if you sign a legal document and there are handwritten changes to it, you must initial near the change to acknoledge that the change was made before you signed, since they made the change after you signed your initials will not be there and you will have some proof.

You might also try to find your original copy of the lease that you got the last time you signed (if you got one, and if you can find it among the chaos of moving) if it shows that you signed from 05-06 then you would have proof that they fruadulently changed the contract after you had signed it.

Either way I realy think you should get an attorney, even if half your money goes to legal fees you will still get something back plus you would rather pay a lawyer to help you than pay the landlord who screwed you.

Good Luck.

rlloydevans has given you an excellent answer.

I would add that unless you initialled the changed dates they are not valid or enforceable. In this case, even if the original lease states that it was renewed for a full year, I would take the landlord to task over the altered dates and threaten legal action for fraud if they didn't refund the overpaid rent and the security deposit immediately. I would back that up with suit in Small Claims court if they didn't immediately refund both the overpaid rent AND the security deposit.

Edit: With your added information, you do not owe for July. I'd stop payment on the check immediately and advise the landlord that you have done so and if they wish to pursue the issue it will have to be through the courts. You might remind them that altering a legal document can be a criminal offense and you will use it as evidence if necessary.

u did not sign so y ou are not obligated the fact that they altered the lease and forged ur name and content to a new lease makes them liable for fraud. tell them that you will not be paying due to the fraud and u will see them incourt when they take u. provide them with a new forwarding adress so that they may get in contact with. save all evidence. courts rarely side with landlords so im sure will have a good case and will win.