I typically have quite a few addons enabled, even if only for a specific toon.
I can mess around with addons, that's something else to try.

Master Only:
Atlas Loot
Auctioneer (AH Alt only)
Deadly Boss Mods
oRA2 (Raid toon only)
Postal (AH Alt only)
Quest Helper
Recount

All Toons:
Cartographer
Clique
Cooldown Count
Dot Timer
Fubar
Grid (and GridCustomLayouts)
IS Boxer
Jamba
Mappy
Move Anything
Outfitter
Pitbull
Prat