[TYPO3] Advanced Banner management and RealURL problem

[matt]

Christopher- as you so rightly pointed out know something doesn't add up here....and I am going quite insane trying to figure it
out!!!

I'm sorry I am unable to show you the actual site... but I  can confirm that the stutus bar does display the correct link, and when
I copy the shortcut in IE you get something like this....

http://domain.tld/subfolder/products/targetpage.html?no_cache=1&tx_macinabanners_pi1%5Bbanneruid%5D=1

Which should theoretically go to the right page!  When I copied and pasted the url into a new browser and hit enter it still
errored.  So I then tried deleting the GET params off the end.... and hey presto, the link works ok.  So more specifically, it’s the
second GET variable in the URL above that is causing the trouble, e.g. tx_macinabanners_pi1%5Bbanneruid%5D=1

Can anyone suggest whats wrong?  Is realURL not interpreting the GET varibles properly?

Thanks again,