[Typo3-dev] Page is beeing generated?

[Lannsjo]

Been developing a page that outputs different xml depending on the URL
parameters...
The problem is just that it only works once..
When I insert the URL+?uid=1  into the address field in my browser a correct
xml output is generated. (within a second).
If I now try to change the adress field to: URL+?uid=2...the page "Page is
beeing generated" is displayed for like 20 seconds and then the old page is
beeing displayed again...
It seems to be something with the cache, but the
$GLOBALS["TSFE"]->set_no_cache();  doesnt make any difference...???

The only way to make the correct page visible is to open the backend and
press "Clear all cache" and then again insert the new URL address..

Can someone help me with this...
/Martin