Fuck! Alright, let's see if ya'll can diagnose this one (please, I beg you):

My computer at work is screwed up. Hard drive action is slow and sluggish if I try to move a large amount of stuff or access the drive constantly for a long time. Make a small text file and delete it, or try and add a new directory, and there is a noticeable latency that should not be there, but it always works just fine. BUT, try and copy a couple hundred meg of stuff from one folder to another, and it will crash, or if it doesn't crash, it will take several hours to complete. Same thing for trying to format a partition. The delays and errors are most notable when interacting with the CDROM (copying files), but do take place at other times as well. Add some special magic: on two separate occasions, pressing the eject button on the CDROM scrambles the boot sector of the hard drive. The latter time it fries the entire file system as well, leaving gig upon gig of data unrecoverable.

So, it's probably a cable, right? Nope; I replaced them, multiple times. Rejumper? No change. The IDE controller on the board? Nope. Switched channels. That didn't work, so I installed a PCI controller and stopped using the onboard one. No change. Well maybe it's time for a re-format? Tried that once; didn't work. Attempting to try it again, but now the problem is too severe and I can't get the fucking drive to format all the way through without the system crashing. I've tried the old DOS format command, Win2k setup, and the manufacturer's utility. They all crash, every time, but not at any specific spot - just randomly, when they feel like it. Well before the CDROM seemed to be involved, so that might be the problem, eh? Wrong! I took the fucker out and replaced it with a different one. Still doesn't work. Maybe it's direct interaction between any CDROM and the hard drive? Wrong again! The Maxtor util is on a floppy disk, and it can't format the drive either, even if the CDROM drive is completely removed from the system. So obviously, duh, it MUST be the hard drive, right? I mean, I should have guessed that long ago. Right? Yeah. SMACK. Aren't I stupid? Yes, I am. So I guess I'll go replace it... but WAIT! You see, I already HAVE replaced it. The new one - a different model, incidentally - and a drive that I've just had working in another system - behaves EXACTLY the same way.

So we've eliminated now all of the obvious causes. Let me stress that there are NO other problems with this computer, and there never have been. Just incredibly slow, sometimes barely functional communication across any IDE channel on any IDE controller using any cable with any drive or combination of drives.

Forgive my repeated use of the French language here, but what the fuck??? Any ideas would be more than appreciated, and I mean that in a sincere, perhaps even monetary sense. Yeah, if your suggestion is the magic winner that solves the puzzle, I'll buy you a beer. Or a keg thereof. Or a beer factory, if necessary. Help meeeeeeeeeeeeeee!!!! :)