[Mediawiki-l] MediaWiki Installation Problem

[root at wiki.v565.vanager.de]

When I try to install MediaWiki on my Debian Server i always get the
error:

# PHP 4.3.7: ok
# PHP server API is apache; ok, using pretty URLs (index.php/Page_Title)
# Have XML / Latin1-UTF-8 conversion support.
# PHP's memory_limit is 20M. If this is too low, installation may fail!
# Have zlib support; enabling output compression.
# Found GD graphics library built-in, image thumbnailing will be enabled
if you enable uploads.
# Installation directory: /home/www/web2/html
# Script URI path:
Warning: $wgProxyKey is insecure Can't find a writable temp directory
for the XHTML template. Check that the TMP environment variable points
to a writable directory, or that the default temp dir (/tmp) exists and
is writable.

/tmp exists and has the rights 777 (read/write/execute for all).

I already read through several threads not being able to figure out
where _my_ problem is ... probably you can help me getting MediaWiki to
work ...

thanks for help

Thomas Uhde