Flashing Lights Symbol

Here's a weird one that's driving my missus crazy and dioesn't seem to be in the owners' manual. A couple of times she's been driving in full daylight with the light switch set to AUTO. all of a sudden the sidelight symbol appears on the dash and starts flashing. Turning the light switch to OFF has no effect until she pushes on the switch. As we've only had the car (An 06 Ghia by the way) about ten days we're still feeling our way around its' complexities but could anyone explain what's happening. The fact that pushing on the switch actually does something suggests that she's (inadvertantly) turned the foglights on I assume, but it's the flashing symbol that foxes me- the only reference to this in the manual concers adaptive headlights, which we ain't got so I'm in the dark (or not!)