Is it my fault?

[Swift Swim]

Think this site may be dead but worth a shot.

I have a service where I level people virtual gaming characters on a MMORPG game on the internet and get paid paypal. It's only small amounts, usually around $5-50.
I received payment from a new customer of $50, and was going to start later on this evening.
I spent the $50 about 5 minutes after I received it as I saw no problems occuring.
I went on to find it disputed, and my balance at -$48 [I had $2 in there already] as the $50 was spent.

I have been in contact with the person whos account was hacked, and he said it definitely wasn't him. What do I do?
Should I be worried?
Should I pay the $48? I can't really afford it.

[Zyptic]

I would file a counter claim and say it wasn't your fault he was hacked.
Paypal works in weird ways.

[Swift Swim]

I would file a counter claim and say it wasn't your fault he was hacked.
Paypal works in weird ways.

I can't even find an option for it

I hate paypal...Just going to remove all my details and close the account.