Ok thanks a bunch!
I believe the small blocks are not related to the YUY2 problem now. I'm now using the below script for avi's.
The low resolution 352x288 is so i can get high cq on 1 cd and better than bigger resolution with 70-75 cq.
LoadPlugin("D:\Films\Tools\Filters\MPEG2Dec3.dll")
LoadPlugin("D:\Films\Tools\Filters\GripFit_YV12.dl l")
LoadPlugin("D:\Films\Tools\Filters\undot.dll")
LoadPlugin("D:\Films\Tools\Filters\atc.dll")
LoadPlugin("D:\Films\Tools\Filters\dctfilter.dll")
LoadPlugin("D:\Films\Tools\Filters\blockbuster.dll ")
AviSource("123.avi")
BlindPP(cpu=4)
Blockbuster(method="noise",detail_min=1,detail_max =3,variance=0.1,seed=1)
ATC(2,3,5,0.5,false)
GripCrop(352, 288, overscan=1, source_anamorphic=false)
GripSize(resizer="LanczosResize")
Undot()
TemporalSoften(2,7,7,3,2)
DCTFilter(1,1,1,1,1,1,0.5,0)
GripBorders()
Cheers from Big Tea Sipper