I am having the same trouble with the flipping between 2 frames (sometimes it skips between 3 frames) from which only alt-tabbing out and back in gives a temporary relief.
I have spent a couple weeks of real life time and over 290 in-game days trying all the solutions listed on the first page and in all 60+ pages of this thread (seriously, I have tried all of them). I have also used search and found several other suggestions that don't appear in this thread and they also didn't work. The only thing I can think of that I haven’t tried is every single possible driver version for my graphics card (I tried two suggested rollback versions) but I will probably try that, too.
With the solutions offered here and elsewhere I am not able to fix this problem, only reduce the frequency of its occurrence. Some of the "solutions" (they are more like sacrifices, they hide the problem they don’t fix it) do reduce the frequency of this stutter/freeze but it never goes away entirely even with the graphics entirely gutted and battle size at minimum. With everything set to its ugliest setting this problem still occurs after about an hour. This shouldn’t be happening on my system, I don’t have background programs running (I disabled everything including many processes at startup, trying to dedicate my machine to this game), and I see here and in other threads people having the same problem with different graphics cards (or at least some of them make it sound like it’s the same problem).
I love this mod to death or I wouldn't be trying so hard to get it to function. I really loved the flawless 300+ person battles I experienced in native warband and, before trying PoP, had little hope keeping interest in this mod with all the sacrifices entailed in getting it working. But the mod is so well done I was able to convince myself to tolerate the terrible graphic settings and intrusive alt-tabbing workaround for some time. It is impossible to get through a large series of battles (800+ combatants) with the limit at 100 participants without having to alt-tab once during the second or third skirmish, and it occurs with increasing frequency from thereon. (And yes, although I would refuse to play this game with lower than 100 participants permanently, I did test it on the lowest settings just to see if I still experienced the stuttering, like I said I tried everything to try and weed out the problem).
Intel(R) Core(TM)2 Duo CPU E6850 @ 3.00GHz 3.06 GHz,
3.25 GB or RAM,
AMD Radeon HD 6800 Series [VX2235wm]
My experience is a repeat of other posters but just to be as clear as possible I will describe it again. My problem is not a freeze or a crash in the normal sense. The game stops abruptly, sound still plays, and two or three frames will play, forward and then in reverse, endlessly, unless the user alt-tabs and reenters the game, where it resumes normally although some action happens during the alt tab. This is how it appears in battles. It also appears outside of battles – in conversations, in shops, or merely clicking on a troop type in the party screen (just selecting it, not talking to soldiers or whatever). Sometimes in the party screen, when selecting a troop, a stretched texture of the previous troop you were looking at will persist in the display. In all situations, whenever the “flipping” occurs, inside or outside of battle, alt-tab serves as a temporary workaround. The higher the graphics settings are set (texture quality and number of battle participants seeming to have the greatest impact) the sooner and more frequently this problem manifests – but regardless of settings and all attempted fixes, it will always happen eventually. Battles seem to bring it about the quickest, but I remember about a dozen situations where an hour or two on the campaign map will also produce the problem.