Comodo AntiVirus and multi-user


I Comodo Antivirus build version, Windows XP pro with 4 accounts ( 1 as administrator and the others are limited accounts ).

When I start my PC using the administrator account, all is OK. But when I log off from this account to change account, Comodo Antivirus send me an error message :

E:\Program Files\Comodo Antivirus\Cmain.exe

Currently Comodo Antivirus does not support Swith User.
CAVS is already using in User : A. Please log off A and try again.

( A is the administrator user )

After that, CAVS is no more running.

Can you tell me where the problem comes from ?