what problems r possible with a jailbroken itouch?
 

I'm buy one that's already jailbroken and while I inteneded to do it myself is there anything I should worrya bout or test? Its a second gen

nope.
i jailbroke mine few weeks ago no problem.

Well, the only problem I know about with a 2nd gen that's jailbroken, is that if they have installed "SBSettings",
the Autolock function does not work and will cause your itouch to stay locked forever,
unless you double tap the home button to play a song, and then plug the itouch into the pc so that it loads up itunes.
From there, you can disable it!

Got my itouch when it first came out and jailbroke it pretty much instantly. Never had any issues what so ever

Well, mine is slightly different. Jailbroken iPhone and haven't looked back. All the free apps I want and no problems whatsoever.