:thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

Cheers mate, that indeed was the root of the problem. Had increased font size in windows, switched that back to default and alas all is well. Interestingly the display resolution in windows and nvidia control panel both still showed 2560x1600, but the 150% increase in font size was obviously interpreted by IS as a 150% reduction in screen real estate.

Thanks heaps for the help.

Cheers
Noids