Fatal Error obtained while translating in xilinx ISE 5.2

[Sriram]

Hi ,
In my design I had instantiated a multiplier and performed a MAC
(Multiply Accumalate operation using that .
The synthesis step worked but when I try the Implementation , the
translation step fails with the following error.

FATAL_ERROR:NgdBuild:basnbmain.c:1910:1.71.4.1 - Design is empty

If anybody knows the fix to this problem do help me out.

thanks,
Sriram