I was attempting to pair with an embedded bluetooth device using the EMDK v2.3 - an EMDK that has worked on previous Motorola devices such as the MC75.
When attempting to pair using the Symbol.WPAN.Bluetooth.Bluetooth class, the device receives the pair message but then the EMDK throws ab Exception with message "DiscoverServices : Failure in find service API calls : Can't find PInvoke DLL 'BTInterface.dll'."
The stack trace looks like this:
at ag.l(RemoteDevice A_0)
at ag.n(RemoteDevice A_0)
at ag.j(RemoteDevice A_0)
at Symbol.WPAN.Bluetooth.RemoteDevice.Pair(String AuthenticationPIN)
I can confirm, once upgrading to the latest version of the EMDK v2.4 fixes this issue (v2.04 of the Symbol.WPAN.dll assembly).
You can download the EMDK v2.4 for .NET here: http://support.symbol.com/support/search.do?cmd=displayKC&docType=kc&externalId=12874&sliceId=&dialogID=196190455&stateId=1%200%20196186434