As you are in mixed mode, something which I missed initially, there are a few things which you might like to consider, if you haven't already:
Win2K clients in a mixed mode domain default to Kerberos Authentication, meaning can't be authenticated by the NT BDC. Which means that win2k clients go up to Win2k DCs and pull login scripts from there. That points to AD hence.
If you've managed to authenticate the Win2k client at the BDC then are the scripts being replicated fine? As far as I know LmRepl is replaced by NTFRS upon upgrade and both cannot coexist. Admins have to manually arrange for the replication of scripts from Win2k DCs to NT BDCs.
Can your NT and Win9x clients able to get scripts over RAS?
Mubashir
muhammad.mubashir@sbp.org.pk
Imagination is more important than knowledge. - Newton