can't connect to win2003 shared folder

When browsing to a win2003 server to access/map to a
shared folder, I get \\server not accessible. The shared
name could not be found. It works well with XP
workstations. Is win9x even capable of accessing win2003
shares? We have an NT4 domain.

We Have A Lot Of Win 98 Client.
We Moved Our Domain
From Win 2000 Professinal Domain
To Win 2003 Server Enterprise Domain
Now...
Win 98 Client Logon To Domain.
But After Sometimes It Is Lost its Authority...
Example :
Machine 1 = MATRIX (Win98)
Machine 2 = NEO (Win 98)

They Are Loging To Domain..
And MATRIX Looking NEO's Shares Or Printing To NEO's Printer

After 10 or 15 Minutes...
MATRIX Don't Look NEO's Shares Or Don't Printing To NEO's Printer
Because Again Wanting Password ...