This comes up with Joomla Mobile Plugin enabled. Joomla 1.5.18 On install, received a blank page but upon refreshing, found the component installed.
php 5
mysql 5

public_html/plugins/mobile/terawurfl/TeraWurfl.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /xxxxxxxxxxxxxx/public_html/plugins/mobile/terawurfl.php on line 25

In most cases blank screen at install means that your server is limited in resources and Joomla has no time/memory to unpack/copy MobileJoomla archive (check your error_log for info about the error). Try to unpack it to Joomla’s tmp directory and do install from the directory.

PS. If Joomla says that MobileJoomla is installed, then uninstall it before (and if uninstalling fails, remove components/com_mobilejoomla and administrator/components/com_mobilejoomla directories and remove com_mobilejoomla-related lines from #__components table).