When I target a valid Virtex-5 part, the following error message occurs:
"ERROR:Data2MEM:74 - Unsupported FPGA device name 'xc5vlx50'.
Line #1, File "cmdString".
There is currently no method by which to work around this issue.
Data2mem will support Virtex-5 LX50 and LX50T parts in ISE 8.2i Service Pack 2.