1998 Pontiac Transport Power Sliding Door

When I close the power sliding door, it closes and then automatically opens. Nothing appears to be blocking the door (i.e. seat belt or other object).
This is an intermittent problem as it doesn't always happen.
The only way to close the door when this occurs is to shut off the power switch and close the door manually.
Is there anything that can be done to fix this (inexpensively)?
Has anyone else had this problem?
Looking forward to your feedback, comments, suggestions.....

Have you reset the door yet? There is a blurb in the owners manual on how to reset the door. I have done it and it works.

You must remove the door fuse during this process and that took out my radio. If you know your security code then you are fine. I didn't and had to go to the dealer to get the code (free in my case).

Good luck.

To reprogram the PSD:
1. Disable lockout switch in the overhead console
2. Manually open door all the way
3. Manually clsoe the door all the way
4. Enable (push in) lockout switch in the overhead console
4. Remove radio fuse
5. Wait 30 seconds
6. Reinstall fuse
7. Wait 10 seconds
8. Disable lockout button
9. Open door with any of the 3 buttons (overhead, B-pillar, remote)
10. Close door with any of the 3 buttons.
11. Open and close door again to verify proper function.