I have had some luck after about an hour of trying different things.
Running Fedora 17 64-bit Scientific, Linux version 3.4.6-2.fc17.x86_64
Here is what I did:
0. download qcad 3.0 linux installer (or the tarball, either one works)
1. set qcad-3.0.0-prof-linux-x86.bin to be executable and run it:
$ chmod +x qcad-3.0.0-prof-linux-x86.bin
2. go to install directory:
$ cd ~/opt/qcad-3.0.0-prof-linux/
3. attempt to run qcad binary:
./qcad-bin: error while loading shared libraries: libGLU.so.1: cannot open shared object file: No such file or directory
etc. etc. etc. This is where I spent an hour looking everything up.
4. install 32-bit libraries as necessary and cycle back to step 3:
# yum install mesa-libGLU.i686
# yum install libXrender.i686
# yum install glib2-2.32.4-1.fc17.i686
# yum install libSM-1.2.1-1.fc17.i686
# yum install qtwebkit-2.2.2-1.fc17.i686
# yum install glibc-devel-2.15-51.fc17.i686
this last one is especially important
5. attempt to run qcad binary again:
and now it works like a champ, and my old qcad 2.2.0 works now as well.
hope this is useful for other fedora folk