clinet for xp lock files

[sasa1906]

Netware 5.0
3 stations win98 with 3.0.0. client because there was a problem with newer clients.
The 3.0.0. on win98 connects to a database and there is no problem with reorganizing the database and all works fine.
With a newer client there was a problem with : 3 clients 3.0.0. are connected and working , when 4rd newer client 3.4 tryes to connect to a database it locks files for himself.
I tryed to connect a xp station with xp client 4.91 client from SP1 to SP5.
Same thing. Xp locks files and wont share.
It only works when xp client is alone in a connection with a database , 3 win98 clients disconnected from database.

So could this problem be a NMAS related ??

Or could help to set : on server

Set client file caching enabled = off
Set level 2 oplocks enabled = off

regards