I have seen that before but I haven't been able to figure it out.
If you set your theme back to DeepBlue, the blocks should re-appear.
It's theme related but not.
I had the problem on my home webserver but not my online webhost.

What version of PHP-Nuke are you trying?

Check this topic out
http://www.karakas-online.de/EN-Book...ng-blocks.html