flash dialog box killing upload

Hi folks.  Often when uploading images to VPHOT via the web interface, I get a dialog box part way through the upload that reads something like

A script is causing adobe flash player 10 to run slowly.  Do you want to abort script. Y/N

The upload freezes until I hit "no."  And if I have left the computer uploading, it stays frozen / time out and I have to start the upload again from wherever it stopped.  If I do catch it in time to restart the download, I get the dialog box again later.  This is a real pain.  I sometimes have hundreds of images to upload, but I have to sit and babysit the upload to get it done.  Is there a switch somewhere I can throw to keep it from doing this?  I am using firefox 5, but this isn't new to the particular version of firefox.  It has been doing this since I started working with VPHOT six months ago.

Thanks,

Walt