It looks like google hasn't dropped any of the old links to forum.search.ie
There's a load of dead ones still in the index
*sigh*

It’s strange that Google can’t fix this and I have been reading that even placing a 410 on the pages Google will translate them as a 404, so the bot will keep coming back to index.

I also see those pages are supplemental, apparently, they will stay in the index for a year.

I think there are ways of getting rid of the links... At present they're all giving a 404, so I can't see why the hell they are still included!

The 404 message isnt really stating that the page has been removed, it can be a temporary 'page not found' so the engines are going to keep coming back for an update.

The 410 however is telling the engines the page has been removed forever so stop wasting time coming back - but its a bit strange that Google sees a 410 as 404, I would say thats Google just being stubborn as not to remove data from their index.

Google hate to remove information from their index and it would "seem" this could be the main reason why old urls are still being listed.

There is this thing:
Webmaster Help Center

Which requires you to create yet another bloody Google account of some kind! (I think I now have 10 accounts or something!!)

Ha so I am not the only one that has a number of Google accounts.