Try to understand which components are being placed where, and see if you can detect a pattern there. Maybe you don't understand the coordinate system of the machine. Does it use fiducials to adjust for where the board is placed? Where is the "reference corner" of the board? Is there a test mode where it shows you the offset computed by fiducial measurement?
Create a board placement file that only places one part on the board. Get that to work, then try to get 2 parts to work. Are you using placement data from the CAD package, or teaching the placement position? Do you have solder paste on the board? If not, the parts will bounce around. For testing, put double-sticky tape on the board, and you can check accuracy by looking through the tape.
Sorry, a lot more questions than answers, but you didn't give us much info to go on.
Jon