UnLocker and secure removing of USB peripherals

[gutenberg7619]

I've the annoying problem with secure removing of USB Devices
(specially HD USB2):
often, when i try the removing by click on green arrows in icon-try
bar, i receive
the error message (activity on device).

I've tried the solution with UnLocker but this utility not (always)
solves the trouble!
Moreover, i've the same problem with files on my loacal files:
the renaming is, tipically, the operation blocked.
UnLocker often shows an activity of Explorer on these files.

Suggestions? [malware?]
(i've winxp pro)

 

[M.I.5¾]

I've the annoying problem with secure removing of USB Devices
(specially HD USB2):
often, when i try the removing by click on green arrows in icon-try
bar, i receive
the error message (activity on device).

I've tried the solution with UnLocker but this utility not (always)
solves the trouble!
Moreover, i've the same problem with files on my loacal files:
the renaming is, tipically, the operation blocked.
UnLocker often shows an activity of Explorer on these files.

I have come across this on OEM installed versions of windows where it hasn't
been quite set up properly. USB peripherals should be set up with write
through cacheing (optimised for removal) and indeed the OEM vendor (name
withheld to protect the guilty) had set up the system to do this. Well,
they had - but, somehow, not quite. Somehow the system had remained stuck
in write back cacheing (optimised for speed) despite the alternative being
selected. Since write through had been officially selected, the safely
remove hardware thingy didn't force a cache flush when you stopped the
device. Instead it reported that the device was active (in reality the
cache hadn't been flushed). If you waited for a period of time (half a
minute was usually enough), the cache flushed and the error was no longer
reported (provided another write hadn't taken place).

Unfortunately I never got to the root of the problem before the machine
mysteriously sorted itself out and started behaving properly. It is just
possible that some Windows update fixed it.