FF Pistonheads using modify headers gives Bad Request!!

[69 coupe]

Right its not a biggy, I sometimes use an O2 usb dongle to get online. problem is O2 compress the http data and pictures are then displayed in very low resolution.
You normally have to hover the mouse over a image where a pop will offer press shift + r to improve the quality of one image, or shift + a to improve the quality of all images on the page. This makes most websites look ste.

To overcome this there is an add-on program called Modify Headers for FF, http://modifyheaders.mozdev.org/
this has the effect of disabling the compression and thus showing websites how they should look normally.
(note using latest versions, and have had this problem for approx 6 months)

Every site I visit works fine except Pistonheads.
click on my normal link http://www.pistonheads.com/gassing/default.asp?h=0... which results in PH webpage diplaying in large bold font Bad Request
If I disable Modify Headers Pistonheads work fine.

The two commands that Modify headers uses are
Add Cache-control = no-cache
Add Pragma = No cache
I'm 99% sure it is the Cache-control = no-cache that is the one that causes the Bad Request.

Not a big deal, as I disable Modify Headers for PH, but thought you would like to be aware.

[RacingPete]

That is very interesting.

We have to use the cache headers to bypass proxy, squid and other servers but I will look into this further as we have had a few people moaning about bad requests page and it is good to understand what is causing this.