Boot Camp/Target disk mode help

Hi, recently I've been going through some troubles with my iMac. The problem is, whenever my firewire hard drive is plugged into my mac, the windows splash screen will show but never loads to windows. If i unplug the firewire, and then restart my computer into windows mode, it works just fine. I wonder if this has anything to do with Target disk mode, because i'm not quite sure how that works out either. Whenever I start my mac, i hold down the ALT key and i have 3 partitions to choose from: Mac, Windows, and another firewire icon. help, anyone?