Is it CheckPoint or is it MS IE5.5??

[Footnotes]

We recently moved from a Raptor FW to CheckPoint NG (nested behind a Raptor). Starting about this time we had a number of users reporting that they can get to the desired website, but then get the "The page cannot be displayed" message. This happens when they use a search engine or try to bore down into the site.

Some pertinent facts:
1. Nested firewall setup, with CheckPoint NG on the inside, Raptor 6.5.3 on the outside
2. Problem seems to be with certain web sites' search engines
3. The sites work inside of our firewall when using Netscape to view them (no proxy necessary), but fails with MSIE (regardless of proxy settings)
4. The sites work outside of our internal CheckPoint firewall using MSIE proxying off the Raptor firewall
5. The sites work when using MSIE and proxying to the Raptor firewalls, but only on the first attempt. All subsequent attempts fail with the same generic error message, "Page Cannot Be Displayed"
6. HTTP GET comes from user's browser, response from web server includes
TCP Window Size=0 on failures. On successes, the TCP Window Size is normal.
7. MTU size coming from these sites is no bigger than 1490 Bytes.

Here's the URL that we're having trouble with:

http://www.ziprealty.com/buy_a_home/search/home_search.jsp?metro=virginia

Here's another web site's search engine that's causing us problems:

http://www.fedtravel.com/gsa/Flight...ls=&trains=&PDA=&Home=Y&fcity=SJCN&tcity=LAXN

Any suggestions will be appreciated.

 

[Footnotes]

This problem was solved by a suggestion posted in the Checkpoint Forum....Footnotes