Thanks for your replies.
Some conclusions:
1. Clicking results into opposite behavior: everything on screen, accept the content
This behavior is probably the result of a missing file in the 1.6.4-1.6.5 diff package or simply by an upload fault...Greg wrote: The upload of the complete 1.6.5 package fixes the problem on the servers with fopen set on. Must be a file missed in the diff package.
I have noticed a missing file before. The file output.php is no longer used and is empty available in the 1.6.3-1.6.5 diff package, but isn't in the 1.6.4-1.6.5 diff.
This shouldn't be causing problems, but sometimes...

In the new 1.6.5-1.6.6 diff package is this file present again!
If this is the problem, it should be solve the problem then.
1.6.6 is probably released early next month.
If you don't want to wait for it, please try to upload the full package 1.6.5 like Greg did.
2. Clicking results into a blank screen.
I can conclude this is caused by allow_url_fopen is 'off'
If you or your webhost can change this, your problem is solved.

If not...
Calguy and Ted are working hard on the new release of 1.7.
They will try to solve the fopen problem at the same time. Until then we can't fix this I'm afraid.
Using {old_print} should be a temporary solution for this, like Moonie did.
I hope there is a useful solution for everybody in here.
Grtz. Rolf
ps. Moonie, thanks for the karma
