Slash seems not to be around... I'll try to see what's going on:
As I understand, the problem is that you are logged in correctly to the forum, but IRLDb does not know it.
What links are you using to forums and IRLDb? (I see how you could get the effect by using wrong links, although I don't know how you could get wrong links) It should be:
forums,
IRLDb (the link to IRLDb is directly to a comment page, so you can easily see whether you are logged in) Are you logged in in the first of these links and not logged in in the second one?
What browser are you using? Can you check if the problem remains in another browser?