VPN Client can not access some server

Hi,

I have set up VPN for my Lan. VPN client connected and access most of
the internal resource without problems. But the VPN client has trouble
to connect 2 of my servers (Running windows 2003 Standard and Windows
Web edition) . When I ping the servers with IP or host name, sometime
I got 1 reply, and rest of timed out, but most of time I got all timed
out. But I can ping most of my other servers without problem. (Also
windows 2003 standard).

if anyone knows the solutions, please help. Thanks a million.

John