When I use the 'hyperlink' button the first time RapidPHP is run after my PC has been booted up, the floating window hides behind the editor window, giving the impression that the editor has frozen. The task manager then shows that the editor is not unresponsive which lead me to realise that the hyperlink window was behind the main editor window.
On subsequent use, the hyperlink window comes to the front as would be expected, even after quitting Rapidphp and restarting. This problem is quite solid: I have reproduced it three days in a row. Today I made the editor window very small first, so I could get this screen-shot to illustrate the problem.

I didn't use the hyperlink button on Rapidphp 2008, so I don't know if this issue is new in the 2010 version.
BTW I'm a great fan of this editor!