All my toons are in 'the old world' and outside major citys, no addons atm.

Currently i've seen 2 different types of problems:
#1 After i get my 4th toon in game, i still have almost 1GB left on ram, but when i try to load 5th i get "Failed to read file..." error after awhile. I always wait for each WoW to load before starting with next one.

#2 Couple times even with only 4 WoW's running 1 of them freezes in load screen, BUT my toon IS in game, moving and jumping along others, i can hear Esc bring out game menu, etc. It only fails to show graphics for that particular window. This is why i was thinking it may have something to do with my gfxcard.

..but now as i'm writing this, for the first time after patch i was able to load all 5 wow's in game. Only thing i did differently was that i waited +5min after 4th was finished before attempting to load 5th. Any idea what could be wrong here? ^^