read message window won't stay in correct place

[atownsend]

Hi, I Just installed 4.8.0.4400 to get around network slowness, it's a huge improvement over an old version I had before, but I've a strange problem. I have 2 monitors using extended desktop (XP home). Pocomail is open on Main monitor, but when I open a message to read it, it always opens on the 2nd monitor (which is not normally switched on). I have tried the usual trick of moving it to correct place, then closing the message whilst holding down the shift key. This works until I close & restart pocomail, then it just reverts to the 2nd monitor.
I have played with the position.ini file, and found that the ViewWindow / Left entry controls the window position, but this gets overwritten each time poco starts or closes, and this Left entry seems to get random values written into it. I had it working fine by changing this value, then for some reason it was overwritten with -1000, putting the view window back onto the 2nd screen.
My main monitor is to the right of the 2nd monitor, this I guess is perhaps unusual, I think most people have the 2nd monitor to the right.
Any ideas? it's very frustrating.
Thanks alot,
Andrew