I tried to load up Active@ Boot disk and run Disk Check on it, but it froze at about 22% completed.
It's bad news that a disk check like Active@ would freeze, but a file system scan would probably result in a hangup if you have bad sectors. May I suggest using a manufacturer's disk diagnostic instead?
Let's assume for a moment that this may in fact be the problem, because it is pretty likely if your Active@ scan gets stuck at 22% every time. Sometimes sectors can be physically repaired (and your data restored) by using a program like HDD Regen. A zero fill like Tmagic suggests may also make your disk usable again by making some sectors work and flagging others from use, but HDD Regen is non-destructive. The trial version gives you the ability to repair 1 sector... to see if it works or not.
As far as unplugging your drive, it's not a good idea because simultaneously writing to the drive and pulling the plug can damage your file system or at the very least some of your files. Unfortunately, drives do not differentiate between accidents and abuse.
However, I think it is worth mentioning there isn't really any *hardware* danger (anymore, at least). Even when the plug is pulled, hard drives are designed to park the actuator/head in a civil manner either on a non-data part of the platter (eg. landing zone) or some other mechanism that prevents damage. To do this, manufacturers use all sorts of tricks, but all of them work even when the power is pulled.. like using capacitors, rotational force, springs etc..)
It sounds like the abrupt power off may have exasperated some existing defect or there was some sort of coincidence. This really shouldn't have happened though.
