How come the PP&E Gain/Loss is posting differently to the General and Sub Ledger?

I need to dispose of part of a fixed asset.  I split the asset and then tried to dispose of the old fixed asset, but the PP&E Gain/Loss did not calculate and post correctly on the G/L?  The Gain/Loss listed in Fixed Asset Details is correct, but the G/L is not.  Has anyone else had this problem?  Any ideas for possible reasons and solutions?