Cannot access device (not in user datastore)

I'm using Visual Studio 2005 to target Windows CE 5.0 and 6.0 devices. Up until yesterday I was deploying to a variety of devices without issue. However, this morning I was unable to deploy to one of my devices.

In Visual Studio, after selecting Tools > Options > Device Tools > Devices, my devices are all listed correctly. I can view the properties of all my devices (and the Delete button is enabled for all of them)...except the device I am now having trouble with. When I select this device, Delete is disabled selecting Properties shows this error:

Error retrieving information from user datastore. Property not found.

There have been no changes to either my system or Visual Studio that I'm aware of.

Solution

After struggling with this for some time, I found the following rather drastic solution:

Load the properties of one of the devices that is working and note down the (working) settings
Exit Visual Studio and all other VS tools such as Remote Registry Viewer
Navigate to C:\Documents and Settings\All Users\Application Data\Microsoft\corecon and rename the folder 1.0 to 1.0_backup
Reload the project in Visual Studio. You will see a variety of errors about a device listed as not being available in the datastore. Just keep going until all errors are acknowledged.
Exit Visual Studio
Return to the path mentioned above and rename the folder 1.0_backup to 1.0
Reload the project in Visual Studio. You will notice that all your devices have been lost.
In Tools > Options > Device Tools > Devices copy the default Windows CE 5.0 Device and enter the properties noted in the first item in this list
Repeat for any other device you need to deploy to (typically to enter the IP address for the device)
You can now deploy to devices as normal

Hope that helps anyone who has a similar problem.