Re: [invalid] Fatal error when upgrading to WordPress 3.0.1 with Buddypress 1.2.5.2
Is that ‘Line 4’ custom? I don’t see it in a functions file for a 1.2.5.2 I’ve just test upgraded.
Generally – and it’s not advise necessarily to follow 
– I have never had an issue with upgrading the WP portion of a site and don’t tend to bother deactivating any plugins; I do though take a backup, ALLWAYS, on production sites prior to proceeding.
