Problems building qwt

[P@u1]

Hi everyone,

I just downloaded the newest qwt version (6.0.0) and tried to build it with msvc.
I started the visual studio 2008 command prompt,
cd'ed to the qwt directory and entered
"qmake qwt.pro"
(this worked fine)
and then
"nmake"
It compiled for a while and then this error occured:
Failed to open "c:\Qt\4.7.2\lib\QtDesignerd4.lib" (I translated it from german)
I looked in the folder and indeed there is no such file.
Do I need a newer Qt-Version or what is the problem here?
I'm using 4.7.2, the newest is 4.7.3, is really 4.7.3 required?
Edit: on their website i found:
"Qwt 6.x might be usable in all environments where you find Qt. It is compatible with Qt >= 4.4."

Thanks for help in advance!