Im having big trouble with a large group of Beholders in their Underdark lair. I can handel two at a time, but certainly not four, and they have couple of gauths with them too. My party has huge magic capabilites in Nalia, Aerie and Imoen but still i cant kick their butties

I saw one thing though, some of the groups i encountered started to kill eachother off, yet i cant seem to remember if I had anything to do with it or that it just happened by itself.

Got any suggestions on how i should proceed?

If you see two groups starting to kill each other, step back and wait for one team to win. Then rush and attack the winners, who will be weakened. If I remember correctly, the drow teams usually win, and they are easier to kill (unless you dont already have adamantine armor from dead drow, in which they can be a hassle). The best way I have found to attack Beholders is to just rush them with people who have things like Free Action cast on them, so they cant be disabled. That, combined with Haste or Oils of Speed allow your warriors to keep hitting fast enough to kill them before they can use too many abilities. Plus, just concentrate on one at a time. If its the damage that is stopping you, and not the disabling, kill the gauths first. Hope this helps,
-Brainless One

Memorize Spell Shield if you've learned it. It keeps your mages from being stripped of all their protections by the Beholders Anti-Magic ray. Start with that and then use whatever other buffs you have available to protect your three mages. Then send them in and they can cast away...fireball, confusion, chain lightning and other spells that will affect the Beholders in groups.

There are some useful tips here: http://www.gamebanshee.com/baldursga.../beholders.php

But beware, because some of them pre-date Baldurdash's "fix" of the cloak of mirroring.

The spell Mislead is always an option. Once this is cast neither the Beholders nor the Gauths can see you (or target you) and you can simply sit back and pick them off one by one. A bit cheezy, but always an option.

Cheesy is walking in with the Shield of Balduran and standing there until they've all killed themselves.

Beholders also don't get along very well with Fire Elementals, which I often use to great effect against them as my main battle tanks whilst my other fighters used missile weapons. The further you are away from them logically the less damage you'll take from their nasty rays, so smart usage of summoning spells and knowing when to rush in should see you safely through.

I never did get myself the Shield of Balduran to check out just how cheesy it is...that's something for me to do next time. ;)