Do you mean VirusScan 8.7i Patch 3 and MA 4.5 ?
There is no patch 3 for MA 4.5, nor an ePO 8.7
If so this does not sound like an agent problem, but more like a VirusScan patch install problem and reinstalling the agent will not help.
Yes, sorry the description was not very good.
I have just found another could of machines that have patch 3 on but ePO is reporting as only patch 2
Any ideas why?