Sorry, early Saturday nap...
Something about the partition table, or possibly how it's being presented via USB isn't working. You said you connected this drive directly via IDE though, right?
I don't know what tools you have. Can you give a diskpart dump? i.e. run cmd and...
c:\>diskpart
diskpart> list volume
diskpart> select volume (insert number of volume)
diskpart> detail partition
Luckily the drive is small. Worst case you can use non-destructive recovery software like <a href="http://www.runtime.org/gdb.htm">getdataback</a> to scan & copy to your other drive. Seems like overkill at this point though. Let's see if anything jumps out from the partition info & go from there.