When does seller's responsibility end?

I'm sure this has been discussed before, but a search could not find it.
I sold a Naim DAC (mentioning this because Naim is notoriously reliable) to someone on November 26, shipped on November 27, 2012.
Did not hear anything one way or another until December 19, when seller emailed to say one USB input would not work with his ipod. Well the input worked for me when I had it. I asked him to be sure he was doing everything correctly, including checking for bad cable. I am not sure the input really does not work.
No word again until December 25, when he asked if I would pay for repair. I answered no, because I felt the time period had been too long and my responsibility was over.
Now he has initiated a dispute/claim against me on Paypal. They have put my account in the negative for the amount of DAC until they resolve it.
Sorry for the long post, I just wonder if there is a consensus on how long a seller should be responsible for "sold" gear. I say a week, maximum.
What say ye?
Ag insider logo xs@2xmuzikat
Muzikat, why didn't the buyer go through Audiogon's resolution center? They waited how long and went right to paypal?? Have you been in touch with any staff members? This is extremely fishy behavior on the buyers part for sure.

I have never had an issue here where it could not be resolved quickly. Only recently did I have a problem with a DIY speaker builder but it didn't go through A'gon unfortunetly.

I agree, almost think it is buyer's remorse. Too late for anything but wait for Paypal. I suspect they are asking buyer for an authorized estimate repair.
The bad thing is my Paypal account is virtually frozen til resolved. If I want to buy anything through them, I must first bring my nregative account to zero by depositing $2000, then the amount of any purchase.
Tpreaves is correct. I purchased "electronic" media from a seller and was sent the wrong thing. Paypal stated that they do not cover anything electronic. This has happened to me 2 times with Paypal. So if you purchase a download (hi-rez file, anything PDF, etc) be VERY Careful!

PS. The seller never sent me my correct item and Paypal told me to read the fine print on their site.
This is a decission on how you want to conduct your business. You are listed as a private user, but your current feedback is 1743. This sounds more like a commercial user than private. So, do you want satisfied customers or are you only interested in extracting every dollar possible?
I am not a dealer. That was stated in previous post.
I have never made money on Audiogon transactions. I just like to try a lot of
different gear. Obsessive perhaps, but believe me, I am a private user.
I probably should consider becoming a dealer. My friends tell me this all the
time. :)