Hi Martin,
I'm not 100% sure how you're calling
kc_openAtPosition(), but given your use of
kc_openAboveThisObject() on the test page, I'm guessing that you pass a 0 in the optional fourth parameter (the timeout), to keep the box open until manually closed. You're probably seeing that the box closes when you mouse out, instead of waiting for user input. Is that it?
I believe I know what caused this and how to fix it. Simply put, the cause was me... I screwed up a line in
kc_openAtPosition(). Fortunately, the fix is me-based as well

... here it is:
Change line 103 of kc_positionedMenus.js from:
To:
I can't believe my code editor didn't know that I meant to put that 1 in there! Seems like it's always leaving important stuff out, misspelling things, etc.
BTW, if you want to position the box absolutely because you want to avoid the possibility of it get clipped by the right edge of the browser window, you could check out the new version with built-in collision avoidance; it would automatically bump the box over to avoid getting clipped. I haven't uploaded this version, but if you're interested in trying it, I can get it to you.
Hope that helps... let me know.
Kevin