Php error "Only variables should be passed by reference"

[abortx]

Hi,
Any idea why this error pops up (when using images I understood)?

Strict Standards: Only variables should be passed by reference in /var/www/vhosts/wpu.worm.org/common.inc.php on line 506

http://wpu.worm.org/de-activistisch_manifest
http://oscillator.worm.org/phpmyinfo.php
Thanks!

[abortx]

Ah, answering myself, was just simply needing an updated version of hotglue : p