iGuidance has this nasty habbit of saying "Please find the nearest road", when driving down the center lane of a highway, and the GPS still has a STRONG lock. (I have had it do it in the DEMO mode! )
That and the "Ding!"
Put either one or both of the files in your iGuidance/Snd folder, and they are a thing of the past. They are just empty .wav files. I suggest backing up the 2 sounds in your IG folder, in case you ever want to revert to having them.