Browser and/or Flash player compatiblity issues

[Wurzagg]

I'm working on a game for which I recently released a playable demo (http://www.sergiovanpul.com/GDR/flowerGame11.swf), or so I thought.
I sent this link to many of my friends, but I've gotten replies from several people that the user interactive parts of the flash movie won't work.

They can move the cursor and see the textfield attached to it change. But they can't pick up and drag the seeds from the upperleft corner. I've created the game in CS3 with AS3, and exported with minimum Flash player 9 compatibility.

I can run the game just fine within the flash development environment and in a standalone FP9. It also works in a browser plug-in FP10 in Firefox 3 and FP9 in IE7.

Can anyone with some compatibility expertise make any suggestions about the cause of this problem. Your help is appreciated.

[Krilnon]

I would first recommend that you try to reproduce the error yourself, just in case your friends are doing something silly. Also, figure out what version of Flash Player they have, etc.

[Wurzagg]

They are also using IE and/or Firefox with FP9 or 10. Some people I got a response from are multimedia designers themselves, so they know how to run a Flash game.
In one case the problem was solved momentarily when upgrading from FP9 to 10. But later the problem popped up again. In another case the problem was solved by zooming in on the Flash Player?!

I just can't make heads or tails of it. The condition under which the problem occurs (and is sometimes solved) seems to be completely random. So, where to target my search next?