i have a problem with PTZ camera. I'm using a canon VCC4 and i'd like that this camera can center a green blob: so if blob is on left of FOV, camera rotate in counterclockwise and viceversa if blob is on right of FOV.
This is my simple code:

for (i=0 ; i< blobfinder->blobs_count; i++)
      green = (blobfinder->blobs[i].color&color) >> 8;
      if (green != 0)
         if (blobfinder->blobs[i].x < 160 )
           playerc_ptz_set(ptz, ptz->pan+0.1 , 0 ,ptz->zoom );
          playerc_ptz_set(ptz,ptz->pan-0.1, 0, ptz->zoom);

But i get this warning message when "playerc_ptz_set" is executed :
"warning : Unhandled message for driver device=16777343:7000:8:0 type=2 subtype=1 len=20"
 Why ???
Nevertheless my camera can rotate but i have noted shaking while my robot move why ???

thanks in advance