Hello,
I think the problem is that hunkusage.dat was created by someone playing
under the administrator account.
If somebody else under a restricted account starts playing the game needs to
overwrite this little hunkusage.dat file. But because the file was created
by the administrator account the restricted account can not delete it.
That's why you get this "can not write to hunkusage.dat" error message.
I am not sure but this might be a possible solution on windows home edition:
1. Go to the administrator account.
2. Delete the hunkusage.dat file.
3. Go to the restricted account.
4. Play under the restricted account.
The hunkusage.dat file should now be re-created with restricted account
privileges etc, so then it should work.
Maybe it will stop working as soon as the adminstrator plays again. So then
you will have to use the same trick again to fix the problem.
Windows xp pro edition has better multi-user support and a possible solution
would be to grant priviliges/access/etc to the restricted accounts to this
hunkusage.dat. (for example: right click on hunkusage.dat and select
priorities from the pop-up menu, then select the user/group name to give
these priviliges too, and simply allow all (like read&write, modify etc).
(This has been untested but it should work and will probably solve the
problem.)
Maybe I'll test it later on.. though I am pretty sure it will work... but
right now I am waay too busy with something else

but give it a try
(This problem is related to different games which use the quake 3 engine,
for example, return to castle wolfenstein, call of duty, call of duty united
offensive, etc )
Bye,
Skybuck.