I've ran into a few bugs. :(

1. [general] Some characters 'dissappear' for other characters. Whilest they are -just there-! I never experience lag on any client, but sometimes I am right on one spot with all characters, but for one (or two) characters, the other two characters seem not to exist for them. Can't target them, etc. I've started to get this more often quite lately. Which is very annoying when it happens in world-pvp. I've yet to get it in battlegrounds and instances, so it might be a 'big zone' related thing? I hope so. :P

2. [keyclone - pip] I'm trying to run a 4 fullscreen on top of each other for arena to use pip to the maximum. Right now I run my three alts at a different resolution and pip isn't fast enough for PvP that way. So in that set up I don't. Pip is on the fly if I run them all in the same size screens. The problem however is that when I have pip set to F1, F2, F3 and F4, when I press for example F3 I want to always go to the char I set to F3, and same etc. But often I can't get to the right char anymore, or they all get scrambled. I don't know what I'm doing wrong really. I used pip before shortly and it seemed to work fine.

Now I just switch once, or twice, and suddenly they're scrambled or don't work at all anymore. :p

I had the first problem too a couple of times. One of my characters couldn't see the other 3, while the other 3 didn't have a problem seeing everyone.
Logging out and in again on the character that had the visibility problem solved it each time. I'm guessing this is a Blizzard issue.

Possible causes I can think of:
- Graphics card doesn't show a certain mesh - not likely, because the character is probably a composite of meshes and it's not likely that they all aren't shown. You should probably then at least see a shadow if this was the case.
- Bug in Blizzard's visibility algorithm (not likely)
- Bug in Blizzard's network replication or other network logic (very likely)

1 - This is a sycnronization issue. if you run away (long ways) and run back the player who isn't seeing the others will start seeing them again.... but you have to leave the overall bubble of awareness. In most cases its faster to relog. This is a blizzard issue not keyclone or multibox.

2 - PIP gets wonky if you spam buttons in my experience. I play 4x1 and just deal with the high latency switches since I don't pvp. I have noticed that if I hit the hotkey for the region I'm currently in I can't switch until I manually change focus, swap that region with something else, and then things will work fine.

For example...

Regions 1-5, 1 is full screen with hotkey Num+, 2-5 are smaller with hotkeys Num9, Num6, Num3, Num.

Focus region1
I press Num3 the switch happens.
I press Num3 again, nothing happens. (Nor should it.)
I press Num+ it doesn't reset to default positions.
I press Num1 it doesn't reset to default positions.
Focus Region2
Press Num3 - They switch
Focus Region1 - Switches behave as normal again.

I'd play with it and see if thats the behavior you are seeing, I figured it was probably something wonky with Vista, if thats not the case we should bug Rob to fix it :).

Yeah, I get pretty much the same that you get. I just get impatient in pvp and start spamming like amd and one time I even had keyclone stop working completely. :p

I figured it might have had something to do with all regions being on top of each other in my case. When I press F1 I just want my first account to be on top, F2 the second, F3 the third, etc. If I repeatedly press on key, it should just get that window in front once and not work afterwards.

But since, PiP works with regions, it keeps trying to swap regions around? PiP is made for windows scattered over your entire desktop dimension I suppose. Maybe it might be an idea to add a 'nerfed PiP' that doesn't actually change regions but merely 'activates' the target WoW window to be on top, on the fly. For those who want on the fly switching mainly for PvP purposes and have there regions stacked on top of each other for the best switch latencies..

Since I play four shaman, I hardly -need- to see all chars at the same time in PvP. And for questing and such I can just use my 1x3 set up over two screens. :p