I run Collatz in a second directory on my second video card. V1.09 has no problems with it and v1.16 had no problems with it either. I'm using port 9999 to connect to my second BOINC client. If I use both videocards (GTX-550 & GF8600GT) in 1 BOINC all project that can use the GTX-550 will try to use the 8600GT too resulting in errors. So I start normail BOINC with a cc_config.xml file with the setting <use_all_gpus>0</use_all_gpus> and in my second BOINC directory with <use_all_gpus>1</use_all_gpus> and <ignore_cuda_dev>0</ignore_cuda_dev>. Only Collatz seems to run on my 8600GT and I dont want the card to go to waste. My GTX-550 runs all other GPU projects I run, SETI, GPUGrid, Einstein and MilkyWay.

I don't run v1.25 as it won't give me access to the program. I can show you the logs of v1.09 to let you see that this setup works. V1.16 has run normally for a week too with this setup (I started using BoincTasks 1 week ago). I can show the daily logs from v1.16 too when it still worked.
Which log would you like? The daily log-file or the startup log-file (which is from v1.25; I guess v1.09 doesn't have this feature)?
Here's my daily log from nov 4th. It's the complete log-file:
Start logging
04 November 2011 - 15:05:43 BoincTasks is closing down all threads
04 November 2011 - 15:05:43 BoincTasks has closed down all threads
Start logging
04 November 2011 - 15:05:53 BoincTasks version: 1.16
04 November 2011 - 15:05:53 Language ---- User: 1033 (ENU), System: 1033 (ENU), Selected: 0 () Used: 1033 (ENU)
04 November 2011 - 15:06:00 Start BOINC client ---- The BOINC client was already running
04 November 2011 - 15:06:01 Maximum number of computers: Unlimited
04 November 2011 - 15:06:01 Computers ---- Labtop , 169.254.0.2
04 November 2011 - 15:06:01 Computers ---- Windows-7-PC Collatz , localhost
04 November 2011 - 15:06:01 Computers ---- Windows-7-PC , localhost
04 November 2011 - 15:06:01 Connect ---- Connected to: Host: localhost, Windows-7-PC Collatz, Port: 9999, BOINC Version: 6.12.34
04 November 2011 - 15:06:01 Connect ---- Connected to: Host: localhost, Windows-7-PC, Port: 31416, BOINC Version: 6.12.34
04 November 2011 - 15:06:01 Connect ---- Connected to: Host: 169.254.0.2, Labtop, Port: 31416, BOINC Version: 6.12.34
04 November 2011 - 15:06:07 Connect ---- Connected to: Host: localhost, Windows-7-PC,Port: 31417, TThrottle Version: 5.10
04 November 2011 - 15:06:07 Connect ---- Connected to: Host: 169.254.0.2, Labtop,Port: 31417, TThrottle Version: 5.10
04 November 2011 - 18:38:27 Synchronize with manager ---- Completed on computer: Labtop
04 November 2011 - 18:38:27 Synchronize with manager ---- Completed on computer: Windows-7-PC
04 November 2011 - 18:38:28 Synchronize with manager ---- Completed on computer: Windows-7-PC Collatz
No problems that day and I didn't reboot (or just once) that day I guess. That's why it's so small.
The second BOINC client I have to start with a shortcut, and I always have a command window open although it's minimized to the taskbar. This technique to run like this is described on one of the BOINC or project forums. It also worked with BOINC- manager. I just had to start a new manager window with IP 127.0.0.1:9999 as computer name.