[p4] Files mistakenly appear in "Local not in Depot"

[Sergio Nasi]

Hello,
I'm facing an odd behaviour when a new client workspace is created by one 
of my users.
This user installed windows XP client version dated March 23rd 2007 on his 
computer.

We tried this multiple times and this is what happens in summary:
1) Create client and specify file mapping
2) Add files to revision control: for example MY_FILE.doc
3) Submit changelist: files are correctly copied to the server since I can 
see and open them from another PC in the "Entire Depot" view. Moreover, 
files are set to ReadOnly on his local file system

Now this is when the strange thing happens:

4) The user changes view to "Local Files Not in Depot" and he can see 
MY_FILE.doc (!?)

I tried to go through the same steps with his own user accout but from a 
different PC and I could not reproduce this problem, i.e. files added to 
revision control are not appearing in "Local files NOT in Depot".

This is driving me crazy.

Have you ever experienced anything similar or have some suggestions?
I'm not a top experienced p4 admin so any help is welcome.

Thanks a lot in advance
Regards
Sergio Nasi