As I said - you're using the wrong qmake.exe...
You build Qt4.1.1 with debug in C:\Qt\4.1.1 but you run qmake.exe from 4.1.0 in C:\Qt\4.1.0. This 'old' qmake is using the library-paths from 4.1.0 and not the paths from 4.1.1.
Rerun qmake (c:\Qt\4.1.1\bin\qmake).
Bookmarks