Don't know if issue with boinc manager or 3.43 rosetta, but it forcibly(i have set it not to open) starts a window that shows the screensaver graphics. Also no progress seems to happen progress bar in boinc manager.

Is that the black text screen? I was wondering what it is...

Happens with my PC too - both Rosetta and Ralph. It started after I updated Windows (7, 64Bit) today.

No progress, windows are recreated every few minutes.

Same issue here. I think you hit the nail on the head. My problem started after the Window 7 update.