RSS feed - Search upon startup

[GaryT]

Once upon a time I had installed the BBC news service onto Firefox, so
that it was available from an RSS button, somewhere up on the toolbar.

That was long ago.

Now I've found that Ubuntu is still checking in to the BBC service every 
time I start the machine.  I want to stop it.

Can someone tell me where/how to find the cause.  Where and what would 
be causing this to happen.  Firefox does not start when the computer 
starts, so it must be something that was installed at the time.

Much appreciated
GaryT