The BlackBerry Bold can randomly reset when it is knocked. The reset is caused by the battery being slightly loose.
Solution? Folded Post-It note on the inside of the Bold back cover.
The Palm Treo 650 SIM card used to shake about, causing a “No SIM” error. Wedging a small piece of business card behind the SIM card fixed that.
And BlackBerry have used the same trick themselves with the 8310 Curve. If you look carefully at the picture left, you’ll see the foam RIM have attached to the cover.