If you specify a custom command file (.do) that resides in a directory with spaces in the directory path, Project Navigator does not send the correct command line to ModelSim.
The problem is in the %XILINX%\data\projnav\scripts\dpm_flowUtils.tcl script, and can be fixed by changing the following line:
puts $_DoFile "$_VLog $_OtherVLOGOptions \"$_File"
to:
puts $_DoFile "$_VLog $_OtherVLOGOptions \"$_File\""
Additionally, the ".do" file will be located correctly if it can be specified using a relative path.
This problem has been fixed in the latest 8.2i Service Pack available at:
http://www.xilinx.com/xlnx/xil_sw_updates_home.jspThe first service pack containing the fix is 8.2i Service Pack 1.