Just dug out some offending item from the arma.rpt file. Take a look and see if it means anything to you?
Error 'No entry' at 'C:\Documents and Settings\Daniel\My Documents\ArmA\Saved\missions\RPG_12_Quarantine_V2_2.Sara\continue.ArmASave/GameState/Variables/Item9/data.value'.
This is the line that happens before the failed to load save error.