Problem with Link

Hi, I have a problem with Link. I have created Link with FileResource, so when you click on the link, you can download the file. When you use Opera or IE everything works fine, but when you try download the file using Firefox browser then there is Communication Error.
Workaround for that problem is opening link in the new window (method: setTargetName), but I have to do that only for Firefox (I hope). I think it is a bug, maybe someone knows something about that.
Best Regards,
Arturo