I have exactly the same problem when i`m trying to open my swf-pano in browser.
I get this message:
ERROR: download of "com_temp/as3Thumbsforkrpano.swf?TheXML=./gallery1.xml" failed
Plugin call code:
Code
<plugin name="thumbnails"
url="as3Thumbsforkrpano.swf?TheXML=./gallery1.xml"
...
Klaus told somewhere, that the reason is to call that file another way, but i`m not well skilled at programming and still can`t understand, how to use thumbnails plugin online in swf...