SME6.01-01: DNS request do not resolve from /etc/hosts

Hi

I have several SME 6.01-01 with same error:
some times it do not answer to dns requests for his own name.

Look:
Workstation (several OSs: W9x , W2K e WinXP) has SME server as primary DNS.
SME server has on his /etc/hosts the entry:
192.168.x.1 mail mail.localdomain

but when workstation try to get access (web access or ping) to mail.localdomain SME server do not understand mail.localdomain as himself , send the request to default gateway and def gat use a internet DNS, so workstation receive the external IP of server.

So my PHP applications do not work anymore, my browser cannot access anymore my server intranet...

I have success to restore internal resolution (some times) by disable NIC interface and enable it again. Some times I need to do a ipconfig /flushdns too.

Any tips?

Thanks

Jáder