When using ApacheLogin? we get taint error

Assertion failed!
 at /var/www/foswiki/core/lib/Assert.pm line 64
   Assert::ASSERT('undef') called at /var/www/foswiki/core/lib/Foswiki/Store/RcsFile.pm line 843
   Foswiki::Store::RcsFile::readFile('Foswiki::Store::RcsWrap=HASH(0x9feedac)', '/var/www/foswiki/core/data/Main/KennethLavrsen.txt') called at /var/www/foswiki/core/lib/Foswiki/Store/RcsFile.pm line 192
   Foswiki::Store::RcsFile::getLatestRevision('Foswiki::Store::RcsWrap=HASH(0x9feedac)') called at /var/www/foswiki/core/lib/Foswiki/Store.pm line 261
   Foswiki::Store::readTopicRaw('Foswiki::Store=HASH(0x9f2b62c)', 'undef', 'Main', 'KennethLavrsen', 'undef') called at /var/www/foswiki/core/lib/Foswiki/Store.pm line 123
   Foswiki::Store::readTopic('Foswiki::Store=HASH(0x9f2b62c)', 'undef', 'Main', 'KennethLavrsen', 'undef') called at /var/www/foswiki/core/lib/Foswiki/Prefs/PrefsCache.pm line 142
   Foswiki::Prefs::PrefsCache::loadPrefsFromTopic('Foswiki::Prefs::PrefsCache=HASH(0xa7babec)', 'Main', 'KennethLavrsen', 'undef') called at /var/www/foswiki/core/lib/Foswiki/Prefs/PrefsCache.pm line 71
   Foswiki::Prefs::PrefsCache::new('Foswiki::Prefs::PrefsCache', 'Foswiki::Prefs=HASH(0xa48acf0)', 'Foswiki::Prefs::PrefsCache=HASH(0xabdb188)', 'USER KennethLavrsen', 'Main', 'KennethLavrsen', 'undef') called at /var/www/foswiki/core/lib/Foswiki/Prefs.pm line 106
   Foswiki::Prefs::pushPreferences('Foswiki::Prefs=HASH(0xa48acf0)', 'Main', 'KennethLavrsen', 'USER KennethLavrsen') called at /var/www/foswiki/core/lib/Foswiki.pm line 1512
   Foswiki::new('Foswiki', 'undef', 'Foswiki::Request=HASH(0xa0ce8d8)', 'HASH(0xa0c2188)') called at /var/www/foswiki/core/lib/Foswiki/UI.pm line 170
   Foswiki::UI::execute('Foswiki::Request=HASH(0xa0ce8d8)', 'CODE(0xa0ce5cc)', 'edit', 1) called at /var/www/foswiki/core/lib/Foswiki/UI.pm line 120
   Foswiki::UI::handleRequest('Foswiki::Request=HASH(0xa0ce8d8)') called at /var/www/foswiki/core/lib/Foswiki/Engine/CGI.pm line 26
   Foswiki::Engine::CGI::run('Foswiki::Engine::CGI=HASH(0x9ec4198)') called at /var/www/foswiki/core/bin/edit line 42

For help, please send mail to the webmaster (root@localhost), giving this error message and the time and date of the error.