Copy of my post on isboxer.com forums: http://isboxer.com/forum/viewtopic.php?f=4&t=706

----------------------------------------
I've been happily dual boxing using ISBoxer and Jamba for months, but my setup took a major dump recently. (Pre-4.x; it first barfed during Brewfest.)

Config: http://pastebin.com/bpFuZCNR

2 toons: Xapi and Zapi.
2 monitors: one 1680x1050, one 1280x1024. The 1680 is my "main" in Windows, and Xapi is dedicated to it; Zapi dedicated to the 1280.

One copy of WoW.

Focus switch by mouseover (no click needed).

As I said, it was working flawlessly for months; from toon creation until now (level 61).

If I have Jamba "Master" on Xapi, then move my cursor to Zapi, it switches Master to Zapi, as expected.
If I then move the cursor back to Zapi, Jamba Master remains on Zapi. Game recognizes the change, as hitting Esc brings up the menu on Xapi's screen.

Even with Jamba Master still on Zapi, selecting a target on Xapi causes Zapi to target and shoot Xapi's target (as expected).

If using Zapi, Xapi ignores Zapi's target. (Gives "You have no target" message.)

If, on Xapi, I click the Follow macro, Xapi follows Zapi (Jamba Master sitting incorrectly on Zapi).

I checked to see if there are any keybinds I may have inadvertently set, but nothing was obvious.

Help?