I often get error messages such as:
Fatal error: Only variables can be passed by reference in /home/thaispice/public_html/modules/multiMenu/blocks/block.php on line 99

I have found this to happen in several modules, such as multimenu and myalbum. Searching this site revealed very little other then some obsure reference to later versions of php4.

there's heaps on this site regarding it.. and thousands more on google.

yes it's to do with newer php versions and deprecated functions.. but you should just take the advice given in all those replies to this same repeat question..

turn debug off and ignore it.. they are notices that's all, and the newer version of XOOPS will be more compatible with newer versions of php..

*edit* i need glasses.. fatal error means there's something wrong for sure.. but you should mention what version of XOOPS you use and what versions of modules you are having trouble with.. there maybe bugfixes for those versions..