mfaktc and CUDALucas side-by-side
 

When running mfaktc and CUDALucas side-by-side the display driver bombs when I hit [i]Ctrl-C[/i] on an mfaktc window; with the following warning.

[i]Event ID: 4101; Description:
Display driver nvlddmkm stopped responding and has successfully recovered.[/i]

It never bombed on me when running mfaktc or CUDALucas separately from each other. I usually run anywhere from one to four instances of mfaktc.

Windows 7, 64-bit; Video Driver Version 301.42; GeForce GTX 580
CUDALucas-2.03-cuda4.1-sm_21-x86-64.exe, 64_41_28
mfaktc-win-64.exe, version 0.18, 64_42_9

Is it possible using different versions of cudart dll at the same time is causing this?

[QUOTE=TObject;305288]
Is it possible using different versions of cudart dll at the same time is causing this?[/QUOTE]

Probably this is the case.

I downgraded the mfaktc to the version that uses the 64_41_28 dll (same as CUDALucas), and the video driver stopped exploding.

[QUOTE=TObject;305288]
Windows 7, 64-bit; Video Driver Version 301.42; GeForce GTX 580
CUDALucas-2.03-cuda4.1-sm_21-x86-64.exe, 64_41_28
mfaktc-win-64.exe, version 0.18, 64_42_9
[/QUOTE]

Same here, with the difference that I use CL: 64_40_17 and mfaktc: 64_41_28 (they both are one step behind comparing with your setup, for speed reasons: I did tests and I selected the fastest of each). The behavior you see is normal.