[Typo3] realurl - strange problem

[Christoph Hofer]

do you probably have similar paths in your domains? such as

domain1.com/start
domain2.com/start

if so, be sure to have the rootpages in realurl/ext_localconf.php 
configured properly according to your domain records, eg.

$TYPO3_CONF_VARS['EXTCONF']['realurl']['domain1.com']['pagePath']['rootpage_id'] 
= 123;
$TYPO3_CONF_VARS['EXTCONF']['realurl']['domain2.com']['pagePath']['rootpage_id'] 
= 456;