Question: I'm using the JFrame plugin with jquery 1.2.6.

It works fine in FF3, however it won't display the requested pages in IE 7.

The jQuery library and the JFrame plugin are called in the included header.cfm.

Page code is here (note: ignore the ColdFusion calls, I don't think they're generating the problem): <http://cfm.pastebin.com/m20c1b013>

Answer: 
When you have a problem like this, the best way of tracking down the problem is to reduce the page to the minimum necessary to reproduce the problem.

*"Ignore the [x] because I don't think that's the problem"* is no good, if you don't think that's the problem, save it to a temporary static page, delete the things you think are unrelated, and then you *know* whether or not they are the problem. Keep deleting things you think are unrelated, and eventually you will either find the bit that's screwing things up when you remove it, or you will end up with a very small file that is:

* Much easier to debug
* Much more likely to attract help from people
* Much better testcase for the times when it's a genuine bug in a library

Not many people are willing to pick apart Coldfusion and table layout code to get to your bug - after all, you're the one with the problem, and even you couldn't be bothered to do it, so why would anybody else?
Being new to JQuery myself, I have found the Developer tools in IE8 indispensible. In the script console I was able to find error messages that gave me the info I needed. Are you getting any error messages? 

There is a "Developer Toolbar" available for IE7. I do not know what it provides for script debugging:

<http://www.microsoft.com/downloads/details.aspx?FamilyID=E59C3964-672D-4511-BB3E-2D5E1DB91038&displaylang=en>