My SRS warning light comes on periodically and stay on until the engine is restarted, sometimes coming on as soon as it goes out after start up, and sometimes coming on after 45 mins driving.

Any common culprits I should be looking at for intermittant problem?

Will try to get a testbook on it when light showing this week if I can.

You will probably find it has logged an open circuit fault somewhere.Disconnect the battery for 10mins then disconnect and reconnect every loom connector you can get at a few times - this may scratch the surface of the connectors enough to make a better contact.The fault will still be logged but the Srs Dcu will try to retain functionality if it can.They will log faults quite easily for low battery voltage etc as well,sometimes even when changing a battery.If after a good poke around all the connectors the warning lamp behaves normally,I wouldnt bother paying to have the fault cleared - leave it till you need other stuff done and get it cleared in the same job.

Have you fixed it ?