According to Garmin they are aware of the problem with the Garmin Drive 40 & 50, they are trying to figure out what causes the device to want to format the T4A SD Card. It seems like a problem with the device.

Garmin has also subsequently discontinued:

• Garmin Drive 50LM (P/N: 010-01532-4B) and Drive 60LM (P/N: 010-01533-4B).

You are welcome to contact us so that we can try to assist you with Tracks4Africa GPS Maps. We can send you a download link which you can transfer to your internal memory at your own risk, as you do not want to overwrite any internal street maps on your GPS unit etc.