Google cache and PR Problem

Hi, a bit of a strange problem here. Bit of background. There are 2 sites, redwidgets.com and bluewidgets.com. These have been around for around 5 years. bluewidgets.com used to redirect to redwidgets.com until about 3 years ago when it became a site in its own right with new content etc. However Alexa still thinks they are the same site listing both domains in its info.

Now on bluewidgets.com on greater than 80% of the internal pages if I view the cached copy usine the Google toolbar, clicking Cache Snapshot of Page, it shows the homepage, and also the PR shows that of the homepage.

However by performing a google search, finding the relevant page and clicking on "Cached" it shows the page correctly cached.

An example of the 2 cache URLs are:
[216.239.59.104...]
[216.239.59.104...]

The fjsDGYTzMPsJ seems to force it to see the proper cached page but I have no idea why. I feel this might be affecting rankings etc but have no idea why.

The response headers and page identification all display the correct information and nothing out of the ordinary.

The server is IIS6 using ISAPI Rewrite but I can;t see that being a problem as it is used on many other of my sites with no ill affects.