Message deletion bug?

Hello.

I have been having this issue that I'm getting a lot of messages, mostly new match invitations from a group I belong to. However, sometimes I don't want to commit myself into anything and I just want to delete all of them without even reading them.

For some reason however, when I click select all and delete, this works like one out of six times or something. Am I the only one who suffers from random behaviour with this option or is this a bug that is already known by the developers? The problem has persisted through two different computers. I'm using Firefox, so I'd guess I'm not the only one in the world. :)

When you click on Select All, then on Delete - when its not working - what do you see ?

I've just tried it on mine with FF3 and its working ok for me, so i need to know what you're seeing.