4200 on board hd tv lag problem

configuration 1:
-ati 4200 onboard
-with sideport /siderport + uma  configuration
-mce/dvbviewer
-ms dtv-dvd video decoder
-ccc 10.4

configuration 2:
-ati 4200 onboard
-with uma configuration only
-mce/dvbviewer
-ms dtv-dvd video decoder
-ccc 10.4

configuration 1 produce lag screen whereas configuration 2 work alright, any ching know what's up with this?