5 boxing ---Massive latency while in MoP Instance

Hi all

I have a i7 extreme quad core and about 6gb of ram. Graphics card is Nvidea GTX 590.

Currently 5 boxing with 5 instances of wow running on this one PC. Have been doing this for years on and off with no real trouble. Now Ive just updated all accounts to MoP and have reached the first instance "Temple of the jade serpent". Upon entering the instance I experience massive "world" latency on at least 3 of my 5 windows.....the world latency can be anywhere between 1000 to 2900+ ms and obviously renders the game unplayable with extreme delays in basic commands. However the FPS remains ok in the 40 to 60 region per window. Upon exiting the instance each character follows again , and upon engaging in basic mob combat the world latency returns to normal for me (about 50ms per window)

I had no issue running some wotlk instances for kicks a day or so before. I'm wondering if this is simply WOW and not my setup. I tried all the usual fixes like my graphic settings are all set pretty low/fair and I have tried reducing/stopping addons.

Has anyone else experienced this world latency issue specifically in MoP instances or knows of it?

Regards GR

Make sure your video setting aren't all on Ultra for each screen. Mine somehow defaulted back to this and caused me some lag running 5x wow's on ultra. I also went as far as to set my main screen to 60fps and 15fps on clones in my 4square split screen.