Wireless connection seems to drop but can still ping?

Hello

I was hoping someone could help me here.

My home lab is set up as this;

Speedtouch 536 ADSL router - Cisco PIX 506 Firewall - Linksys WAP 54G -
Laptop

The router just handles connection to the ISP. The PIX is responsible
for NAT'ing and DHCP. The inside interface of the PIX is connected to
the ethernet port of the Linksys by RJ-45.

I'm using a pre-shared key to be able to authenticate the laptop to the
Linksys WAP.

However, I'm having some connectivity problems. Every 10mins or so, I
will lose connection to the internet. I can still ping the firewall's
internal address but cannot telnet into it or connect to it via HTTPS.
Disabling and re-enabling the Wireless connection on my laptop seems to
fix it until about 10mins later when exactly the same thing happens.
When this problem occurs, I have directly connected my laptop to the
PIX's inside interface and it works perfectly, so the problem does not
seem to be with the PIX alone.

Additionally, removing the PIX from the network and having the router
handle NAT and DHCP results in no problems either. So, it's not
completely the Linksys's fault either.

So, somehow there is a problem between the Linksys and the PIX
firewall.

Does anyone have any ideas?

Thanks in advance.