Your program that is using the .net compact framework is the one failing (not catching an exception), but because you haven't yet installed the optional resource strings for reporting error messages in .net cf apps (a big mistake by the .net cf team by making that optional), you're not seeing the real error message. You're only seeing the "an optional resource assembly containing it cannot be found". Install System_SR_ENU_wm.cab on the device, then reproduce the error. This time you will see a better error message.
Radicomm, Inc. (makers of QuickTalk, push-to-talk over WLAN for warehouse devices - FREE for up to 5 users)