Cannot access some sites with IE or Firefox

[Guest]

I'm stumped. This is the run-down:
2 computers in home network connected to a Airnet AWR014g Router via ethernet.
IP address of Router 192.168.1.1
subnet mask 255.255.255.0
DHCP enabled
Router is connected to a DSL modem

Computer #1
Can access Yahoo.com and all of the avon web site they are attempting to
access.

Computer #2
Cannot access the Yahoo home page but can access mail.yahoo.com. They also
cannot access an area on an avon web page.
Is set up with a vpn. SonicWall virtual adapter.
Local Area Connection 2 is set to a static ip address 192.168.1.102 subnet
mask 255.255.255.0 DHCP/Default Gateway/DNS 192.168.1.1
Pinging www.yahoo.com works. Packets are returned from a yahoo ip address.
The inability to access yahoo or the area of the avon page occur using
Internet Explorer or Firefox.
Turning windows firewall off does not solve the problem
Disabling Norton System Works does not solve the problem
Both Internet Explorer and Windows XP are up to date with all patches
available from MS
Most recent release of jre is installed on both browsers
Adjusting the MTU down does not seem to have an effect.

I can't think of any other information to provide at this time. Any ideas on
what could be causing this?

 

[Chuck]

I'm stumped. This is the run-down:
2 computers in home network connected to a Airnet AWR014g Router via ethernet.
IP address of Router 192.168.1.1
subnet mask 255.255.255.0
DHCP enabled
Router is connected to a DSL modem

Computer #1
Can access Yahoo.com and all of the avon web site they are attempting to
access.

Computer #2
Cannot access the Yahoo home page but can access mail.yahoo.com. They also
cannot access an area on an avon web page.
Is set up with a vpn. SonicWall virtual adapter.
Local Area Connection 2 is set to a static ip address 192.168.1.102 subnet
mask 255.255.255.0 DHCP/Default Gateway/DNS 192.168.1.1
Pinging www.yahoo.com works. Packets are returned from a yahoo ip address.
The inability to access yahoo or the area of the avon page occur using
Internet Explorer or Firefox.
Turning windows firewall off does not solve the problem
Disabling Norton System Works does not solve the problem
Both Internet Explorer and Windows XP are up to date with all patches
available from MS
Most recent release of jre is installed on both browsers
Adjusting the MTU down does not seem to have an effect.

I can't think of any other information to provide at this time. Any ideas on
what could be causing this?

I'd look at the VPN first. Then I'd compare "ipconfig /all" between the 2
computers.
<http://nitecruzr.blogspot.com/2005/05/reading-ipconfig-and-diagnosing.html>
http://nitecruzr.blogspot.com/2005/05/reading-ipconfig-and-diagnosing.html

And check for LSP / Winsock corruption, but this may damage the VPN.
<http://nitecruzr.blogspot.com/2005/05/problems-with-lsp-winsock-layer-in.html>
http://nitecruzr.blogspot.com/2005/05/problems-with-lsp-winsock-layer-in.html