Well I have a bug I suppose, since I can reproduce it every time.
I have an iPad 2, 32GB Wifi. It came with iOS 4.3.3. I went to jailbreakme and jailbroke it. Cydia installed in 10 seconds. Apps installs fine from cydia and if I go through iFunBox. But when I try to go on Appstore and download anything - ANYTHING at all, be it free or not - I get this message:
"Verification required- before you can make purchases, you must tap continue to sign in, then verify your payment info".
Well, I already had my info keyed in, but sure, I'll enter it again. I click OK (it's either that or Cancel) and Appstore pops up again, showing an empty window (looks like the iTunes agreement window) for a split second, then goes back to springboard and download is cancelled.
I've tried rebooting, respringing, turning off and on, same result EVERY time.
My info is correctly entered and works fine on my iPhone 4 and iPad 1, so that's not the problem. The only real difference here is another method of jailbreaking, so I am assuming that the jailbreak has a bug.