Re: Fatal error: Call to undefined function
Probably your using MySQL 4.1, which is not supported by any released version of TikiWiki.
Support has been added to the development versions of 1.9 which you can download from http://de.tikiwiki.org, otherwise you will have to wait until a 1.9.1 release is made (there is currently no eta yet)
Cheers
Damian
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