[Skunkworks] iPhone3G stuck on boot mode after unlock

Hi All, I just downgraded an iPhone3G from iOS 4.2 to 3.1.3 and unlocked using blacksn0w and now the bugger is stuck on boot mode, tries booting for like 5 minutes and then fails and re-tries a zillion times (left it on the whole day yesterday until battery died). All googling just leads to dead ends and I need to pass this on to someone like yesterday - anyone out there had such an issue, and how did u resolve it? ./Ok3ch