Since moving servers approving comments the easy way is no longer possible.
I've posted in detail about the problem on my site http://www.google-adsense-templates.co.uk/wordpress-approve-comments-broken-since-dedicated-server-move.html
Summary is one click approve comment links and the bulk multiple approve comments option no longer works and I have to edit each moderated comment one at a time and select approved then save!
This takes a long time when you have 50+ comments to approve on a site.
Tried disabling all plugins, no joy. WordPress is up todate, had the issue with 2.8, 2.8.2 and 2.8.4 and probably other versions. I'm reasonably sure it's the server not WordPress at fault.
The problem is on a server I moved domains to that was running fine on another almost identical server (both run Virtualmin).
David Law