PIX losing responses from one particular DMZ website

We have a PIX 525 running 7.2(2). Recently, without any network
changes, one particular webserver in the DMZ network became
unreachable. Other webservers in that same network can be reached as
normal. In doing packet captures both inside and in the dmz, it looks
like the page request goes out and the page comes back and gets as far
as the dmz interface. In packet captures on the inside network, an ACK
is received from the server for the page request, and that's the last
thing received on that session. Subsequent attempts seem normal until
that point, too.

We have a standby PIX and we've tried doing a failover to that, and
that device is showing the same behavior.

 

replace the NIC in the webserver maybe