After JB'ing my 3G 3.1, I tried to download "iHandy" and later "ExtendedPrefs", both resulting in freezing at the Cydia completed installation screen. After pressing Reload, a first ring will pop up, freeze, then a second will pop up and rotate forever. I'd reset my iPhone after a while, and it would boot up into Safe Mode (both times), and not be able to restore Springboard. I had to restore to the jailbreak twice.

Does anyone have any fix's/ideas?
Any help appreciated.