As everyone knows, Beholders are very frustrating to fight, as they have a nasty tendency to first dispel all your buffs, then hit you with everything they've got while you're vulnerable. I've got a few ideas that would fix beholders, and none of them would require new technology on the developer's part - it would just require applying them to beholders.
1. Beholder's Antimagic Field dispelling buffs.
SRD Link on Antimagic
Antimagic is supposed to suppress, not dispel it. The technology to suppress buffs already exists with the Globe of Invulnerability spell.
In this case, the developers would simply have to apply the same technology to a beholder's antimagic - as long as a character has the "Antimagic Field" effect on, his buffs are suppressed, but when the field wears off, the buffs return.
2. Beholder's Rays striking a character under the effects of Antimagic.
A Beholder should not be able to strike a character under the effects of Antimagic - they're in the field, so spells, spell-like abilities (such as the beholder's rays) and supernatural abilities should be suppressed. The technology to make a character immune specifically to a Beholder's spells exists via the Beholder Optic Nerve.
In this case, the developers would simply need to make a Beholder's Antimagic Field "buff" provide immunity to a beholder's rays.
Thoughts? These are just rough ideas, but it would make fighting Beholders less of a frustrating experience. Keep in mind I am not whining because I think beholders are too hard, as beholder-hunting with my cleric in von2 and 3 is a favorite pastime of mine, but I think these changes would make beholders a much better foe - you won't feel like you're being cheated every time you fight them.