[TYPO3] popup_manager has no effect

[Tony Lush]

In a TYPO3 4.0.5 site I have installed popup_manager 2.0, but several test target pages are not popping up even when they are set to: width=500, height=400, scrollbars=0. 

I also recreated the link to the page, but still we have no popup behavior. The popup code is properly inserted into the page header. I did try recreating the link, but still could not get the expected action.

Am I missing something here?

Best regards -- Tony