I noticed there is a project file usrp_std.qpf in the
usrp\fpga\toplevel\usrp_std folder but when I opened that file with Quartus
II 6.0, it said that the file was previously opened with an older version of
Quartus II. That is why I created a new project and added all the files
I am also using Quartus 6.0 and I just accepted the dialog windows
complaint and everything compiles good for me.