Whistler WGPX-550 Handheld GPS Receiver

For me, this device worked for about 4-months and then suffered severe file corruption and wouldn't work until I contacted technical support. I also experienced occasional smaller file errors while switching between screens during normal use.
When the unit crashed the company was helpful and responded quickly by emailing the patch dll and executables to correct the problem. This will likely cause you to loose your stored 'favorite' destinations. I searched on line sources of information and noted that I wasn't the only one experiencing the failure.
I suspect these errors are related to their implementation of WinCE. Certain other GPS navigators also use this embedded Operating System and probably exhibit similar issues.