This item is from the Yet Another Enhanced IDE/Fast-ATA/ATA-2 FAQ, by John Wehman and Peter den Haan with numerous contributions by others. (v1.92).
The idiosyncrasies of the 32-bit disk access feature with respect to disk hardware has led to the popular myth that 32-bit file access has similar problems. However, that's all it is: a myth. If 32-bit file access fails, you should first check your filesystem and the programs that use it. As little as a single open file, e.g. from a printer spooler, will cause 32BFA to fail. Oh, and put DEVICE=C:\WINDOWS\IFSHLP.SYS in your CONFIG.SYS, and make sure your SYSTEM.INI contains the correct magic incantations (vfat.386, vcache.386). If this doesn't help, there's a first rate FAQ on this topic (see the net.resource guide for details).