A design with partitions that have preservation routing is fully implemented, then an area group is created for the partition in Floorplan Editor (FPE). When the UCF is saved, the partitions correctly go out of date. After re-implementing, all partitions are up to date. However, if one then re-adjusts the ranges of the Area Group in FPE, and saves the UCF, the partition does not go out of date.
What might cause the problem, and when will it be fixed?
This problem has been fixed in the latest 10.1 Service Pack available at:
http://www.xilinx.com/support/download/index.htm
The first service pack containing the fix is 10.1 Service Pack 2.