media upload fails - browse does not work

Hi there,

i tested with several different OS with no luck

When i upload a new ISO i click on Upload -> Java security popup -> i click ok -> now i click browse - nothing pops up....

I tested with Windows 7, Windows 8, Server 2008R2 - Java is up2date.

All popup blockers are disabled.

Tested with IE8,9,10 and Firefox 26.

Please give me a hint.

Thank you

Alex