FPS problem on specific boss fights

[JIMM-]

hey there guys,
i am suffering severe FPS drop in 3 specific boss fights and i cant find out why, i have very good n high fps constantly on all bosses except for
Elegon and Garajal in Mogushan Vaults and Garalon in Heart of Fear.

Its just these 3 bosses have some buggy stuff going on causing massive lag spikes all over the place and it affects my performance on these 3 bosses..

Anyone suffering the same problem and resolved please help !
i am very certain its not problems on my end as all other bosses caused 0 problems and have almost constant 120 fps all the time

using i5-2500k and radeon hd 6950, 12 gb ram, running win 7 ultimate -64 bit

[Deleted]

Guess you have tried the most obvious of turning off all the addons?

[JIMM-]

i've read reports turning off combat log / recount works for Elegon however for garajal and garalon .. i have no idea

also read some rough, vague stuff regarding the achievements refreshing non stop causing fps spikes but have no solution, need help please !