Cannot use a scalar value as an array in Callbacks.inc on line 65

My server log is full of this error
Cannot use a scalar value as an array in /var/www/html/gallery2/modules/core/Callbacks.inc on line 65

Just by doing a google search, there are three other sites i have found with the same error and they obviously have their debug mode on i guess.

http://www.deftz.de/picstore/gallery-2.2-rc-2/main.php?g2_itemId=917
http://www.apisupport.com/gallery2/main.php?g2_itemId=477
http://martins-fotopage.de/v/west_highland_way/drumquhassle-rowardennan/DSCN1384.jpg.html

Doesn't anybody know how to fix this? i only got it after switching to the extreme theme,
so i don't consider modifying the gallery core files to be a valid solution unless the mod is posted by the gallery2 team.

I am using latest gallery2 2.2.1, X_Treme theme and g2bridge 2.0.14 for Joomla 1.0.12

Any help greatly appreciated.