Probably clutching at straws:
<UL><LI>Came close to crashing<LI>Hard booted<LI>On restart CHKDSK choked at 52% on a removable PCMCIA drive (Toshiba 2Gb - about 25% full) <LI>Further hard boot<LI>CHKDSK now fails on the /F switch (simply reporting FAT32 formatting) and will not run on the /V switch<LI>On checking on a friend's WinXP machine, the "headline" error mentions ufat.dll<LI>The friend's Norton Disk Doctor states the format is unrecognisable[/list]Any last gasp suggestions?

It may be that the File Allocation Table has become corrupted.