Usually problems with Windows Explorer in w2k3 over server Debian 3.0

Hi. I have problems sometimes going to "My Network Places" in the Windows Explorer. Sometimes works OK and sometimes appears an Explorer.exe Application Popup:

<<The instruction at "0x10004160" referenced memory at "0x10004160". The memory could not be "read">>

and the Explorer go out or is blocked and I have to Terminate process. After this; usually the second time who runs Windows Explorer it's OK. We have PC Computer Clients with W2K3 with SP2 and connected over a network with Debian 3.0 Servers.
I read in forums that I have to make a defrag of every client hard disk but this most of times HD are nearly empty. Does It possible that this problem is related to my useful problems printing in our network printers who I was explain in another question of this forum?

LJ4300 & LJ5M Printer Network works only sometimes

I hope any ideas or suggests to obtain any solution to my useful connecting problems. Thanks in advance.