have you tried it yourself ?

it doesn't hang or crash on mine when i press that button, or in fact all three buttons does have problem.

however, i tried 1 thing that just close the garmin automatically on my phone. Set "turn preview to ON", switch to landscape mode and navigate. When u reach a junction where the "turn preview" suppose to display, garmin will close !!! not hang hahaha

u guys try it out and see .. remember, only will happen when turn preview suppose to display, so either u really driving with route or simulating route

maybe they will release an update..this is quite a serious problem

Same as uninstall other application. Application manager >  Installed Apps. Select theme and uninstall.

If you don't want your 5800 to be bulky with leather casing or silicon casing, IS is a good choice although the installation I can say need professional level (steady hand, suitable environment etc.).

For me IS is a must and good scratch protector. My kid always play with my phone and put all around my house and no scratch at all. Honestly, my phone ugly but after a long time, I'm getting use to it and can totally ignore them.