When opening the Constraints Editor from Foundation ISE 3.1i in Windows 98,
a DOS Window named XILPREL opens with the message "Invalid Switch."
The customer should be able to safely ignore this message box.
This problem has been reproduced by Xilinx Development and does not
effect the proper function of the constraints editor.
Note: The constraints editor can be opened outside of Foundation ISE
without receiving this error message.
This has been fixed in the 4.1i release of the software.