Applied EM Grid Control 10.2.0.4 patch set and issue fixed.
Because the 10.2.0.4 patch set is not available on all platforms if the EM Grid Control is 10.2.0.1
then apply 10.2.0.2 patch set and install the patch 4438550.
I don't know if this issue happens on 10.2.03 version. If problems exists then apply 10.2.0.4 if available or contact oracle support.