I tried out BackCountry Navigator for the first time last week while Jeeping near Moab.  The feature set is great.  The user interface is a little quirky, but it didn't take me long to figure out how to use it.  But I was disappointed with the stability of the software.  It crashed several times.  Most of those times I was able to start it back up and continue using it.  But one time after it crashed it was unable to open the map file I had been using.  Each time I try to open it I get an InvalidCastException error.  So now all my maps, waypoints, and tracks were gone.  I was well out of cell phone coverage, so I couldn't just download a new set of maps.  Luckily I knew my way back to town, and I was able to create a new map file and download a new set of maps before heading back out that afternoon.  But if this had happened on the 1st day of a week-long backpacking trip, it would have been very annoying.  Is this a known problem?  Does the software crash regularly for other users, or is there something about my hardware it doesn't like?  I'm very close to buying the software, but this one issue has me concerned.

By the way, I'm using an AT&T 8525 (HTC TyTn) with a bluetooth GPS receiver.

Thanks for the reply.  I have not seen any more crashes in the last few days, so I'm starting to think the crashes I was seeing before may have been related to something in the particular map file I was using those first few days.  Clearly it's not a common problem since no one else has reported it in the forums.

I don't have any shell programs, task switchers, or other programs of those types installed on my phone.

At least 2 of the crashes happened when I carried my phone far enough away from my Bluetooth GPSr that it lost contact.  I wasn't able to figure out any pattern for the other crashes.

Here are the contents of the BCNav2og.txt file:

Ex:Opening DataBase2008-05-20T12:59:46
System.InvalidCastException: InvalidCastException
at CritterMap.BackCountryNavigator.NControl.Tracker.ReadFromActiveTrack()
at CSPocketTerra.MapDatabase.TracksChanged()
at CSPocketTerra.MapDatabase.AddUserLayers()
at CSPocketTerra.MapDatabase.OpenDataBase()
at CSPocketTerra.BCNavMain.ButtonOpenDB_Click()
at System.Windows.Forms.Control.OnClick()
at System.Windows.Forms.Button.OnClick()
at System.Windows.Forms.ButtonBase.WnProc()
at System.Windows.Forms.Control._InternalWnProc()
at Microsoft.AGL.Forms.EVL.EnterMainLoop()
at System.Windows.Forms.Application.Run()
at CSPocketTerra.BCNavMain.Main()
: InvalidCastException

The corrupt map file is 11.6 MB in size.  What would be the best way for me to send it to you?

This should be fixed in 2.6.6. There was some confusion with fixtime on trackpoints.

I got the "InvalidCastException" today and I have installed version 2.66.
I have also moved out of range of the GPS receiver.
The original map and several tracks and waypoints were created on an older version. Everything seemed to work fine on the older version except Google Earth did not import the tracks well.
On the the newer version, the error seems to make opening the map impossible.