0.6.3 Bug?

After updating to Piwik 0.6.3 i am unable to add new Plugin’s that formally worked in 0.6.2. I am using a Windows XP box with Apache2
The Settings->Plugins page loads fine but when i try to enable a new plugin i get:

“Fatal error: Call to undefined method Piwik::prefixtable() in xxxxxxxxx\htdocs\piwik\plugins\ProxyDetect\ProxyDetect.php on line 36”

This occurs for all plugins i try to add… including GeoIP

Fatal error: Call to undefined method Piwik::prefixtable() in xxxxxxxxxx\htdocs\piwik\plugins\GeoIP\GeoIP.php on line 41

I reinstalled and the error persisted.