Here is the reply that I got from a different site...
"It will be a blow or high resistance bulb. The warning goes after 30seconds to free the dash display up for other uses, but it will be in the background display which can be called up on demand.
To check which lamp has blown switch the lights on in a slow sequence, sidelights only, then headlights, then brake lights separately.
When the warning illuminates check the lights that are supposed to be on, including numberplate illumination.
If all are lit check the bulb holders for poor contact."
Yes it was the number plate's illumination bulb...
