Your mishap was probably a result from the way the various drives were accessed, I bet the camera and external HD don't always take the same drive letters?
I am not convinced that the "Remove drive" button is necessary at all. I realise that corruption of files and folders is a possibility, but I have not had that happen.
Obviously it is not a good idea to disconnect while files are open and being saved or edited, but this removal procedure is not part of 98SE, and simple disconnection didn't cause me any grief.......I was always careful not to switch off the USB HD while it might have been in use.
Now using W2000, I am prepared to accept a scolding for disconnecting first but have yet to suffer any snags by doing this.
I'd be interested to see what others have to say.