Dash Warning Symbols

[00lewis]

Hello there I have just got into my celica and the stereo would not turn on, I guess this is due to me recently adding a cable to the Aux bit in back for ipod, however i thought i would be a clever dic and turn the engine on and off while driving to see if it would come back on, It did but then i either stalled in or the engine cut out, so tried again stereo came back on and all appeared to be ok, But a symbol appear on the dash, The seat belt symbol came on but this time it had a full circle over it, and when i parked up i could hear a long beep from what sounded like the boot( probabily about 10sec).

does anyone have a clue what this could mean? perhaps when started engine and seatbelt was already in it confussed it?

perhaps the symbol always displays like this but i have never paid attention to it.

kind regards