VPS not updating setifaceUpdatePackages() failed 0x20000019

have XP 10 clients of which 4 update VPS correctly, 6 however fail to update VPS and return the following messages in aDNM:

Today at 15:31:49 2181048115 D3X8MT0J Function setifaceUpdatePackages() has failed. Return code is 0x20000019, dwRes is 20000019.
Today at 15:31:50 2181040084 D3X8MT0J An error has occured while attempting to update. Please check the logs.

These 6 all had standalone version of Avast 4 previously which was manually removed using aswclear.exe utility. rebooted etc at end, to complete uninstallation. Network version of Avast pushed from Network manager to all devices.

on the client in the error.log I also get the following message:
03/09/2008 16:23:27 1220455407 SYSTEM 1740 avastms conn attempt failed, LastSrv (192.168.16.3:16111) OK. (error 00000000).
04/09/2008 10:04:37 1220519077 SYSTEM 1708 avastms conn attempt failed, LastSrv (192.168.16.3:16111) OK. (error 00000000).

where should I check to sort out the error?