Christian Helle has posted a registry setting on his blog which can be used to toggle the StoneStreet One Bluetooth stack off on Motorola (nee Symbol) rugged handheld devices. Their newer devices (ES400 and MC65) use the Microsoft stack by default.
http://christian-helle.blogspot.com/2010/10/motorola-dual-bluetooth-stack-support.html
Once you’ve made this change and soft-reset the device you can use the 32feet.NET library to work with Bluetooth from your .NET Compact Framework applications on these devices.
In The Hand Ltd 