Post number five is what I used as a guide. This resets the SRS light only and works, I have used this on 3, 6th gen accords all with success. Mine never came back on. It involves shorting out the pins on the MES plug. The plug is above the drivers side kick panel two pin yellow connector. If done properly this procedure takes less than a minute to clear the light. Post #5
http://www.superhonda.com/forum/f13/how-reset-srs-light-59738/
I would try to reset it and see if it comes back. If it does then I would look into it further. The seat belt sensor was replaced under warranty a long while ago but never had an issue with the passenger seat sensor.
EDIT: The video posted above is for the CEL system, SRS is an independent system from the CEL and wont reset using the method above.
Copy and pasted the procedure here: the link above has pics.
1. Locate MES Plug. It should be located near the driver's side fuse panel under the dash. The harness is yellow with two wires.
2. Unplug the MES Plug.
3. Insert one end of speaker wire into MES Plug (one wire in each contact)
4. Follow this sequence of shorting the other two leads of the speaker wire and turning the ignition to "on" (not accessory, not start)
Short and hold the leads while you turn the ignition to on. The SRS Light will illuminate for a few seconds then go off.
When the SRS Light goes off, unshort the wires. The SRS Light will come back on.
Short and hold the wires again. The SRS Light will go off.
When the SRS Light goes off, unshort the wires. The SRS Light will blink twice.
Turn the ignition off.
Start engine as normal. The SRS Light should illuminate for a couple of seconds as normal and then go off.
This series of shorting/unshorting needs to take place within a
4 second window of the SRS Light going on/off each time.