Nothing wrong, I'd say. The Alpha was never clean in the first place and refining the matet simply responds to some artifact that you may not see, but technically are already there like tiny fractions of non-transparent pixels with just 0.1% opacity or something. You could try and render the raw clip out to a format which supports Alpha. The forced quantization might eradicate the offending pixel garbage and you can then apply any refinements to the re-imported clip. The same could be done by pre-composing teh Rotobrush result. and naturally, you might consider adding some garbage mattes/ masks somewhere in there to prevent stray pixels influencing your result. It's realyl just a workflow problem...
first I want to thank you for the fast, and very helpfull reply!
I've exported to FLV and imported the clip again and seens to work fine at first, but I would have to re aply roto brush to use the refine matte, and the pixel are still there even with compression. (With the compression they are visible)
Whem you say to pre-compose the rotobrush result you mean theres a way I can erase those pixels before applying refine matte? Becose the workflow problem is non-visible until I use the effect.
I used a black solid mask on the roto brushed person on my clip, but now instead of blurring the clothes colors the mask is blurred.
thanks again for the help, if you can give me this final orientation I would be even more grateful!