Hello,

First of all it's a great extension, very flexible, but I have an issue with it.
If you check: mindtrick-records.com/mtrtesttesttest/index.php/weblinks/artists
and click on 1 of the images, there are 2 slideshows opening. The one on the background showed up after
uploading the website to a live server. I'm using Joomla 2.5 and Simple Image Gallery V2.5.6

How can I disable the background popup?

First of all please upgrade to SIG PRO 2.5.7.

ok, I did that, but still the same problem?
mindtrick-records.com/mtrtesttesttest/index.php/weblinks/artists

.....ps: ALSO after updating my custom made CSS is gone and overwritten big de default CSS??  :o

.....Does anybody got a clue to resolve this issue??

This must be a conflict with the module your use Random Image Extended.
Disable it and check if the issue remains please.