MacFixit meldt een mogelijke oplossing van je probleem:
WWAN Support 1.0 installs the following files:
/Library/Modem Scripts/WWAN Support
/System/Library/CoreServices/Menu Extras/WWAN.menu
/System/Library/Extensions/IOSerialFamily.kext/Contents/PlugIns/AppleWWANSupport.kext
/System/Library/Extensions/IOSerialFamily.kext/Contents/PlugIns/AppleWWANVerizon.kext
As such, you can try to regain functionality of your device by deleting the aforementioned files, then re-installing the driver available from your wireless access device's manufactuer (e.g. Novatel's driver for the Merlin XU870).
The last two files are tricky -- the best way to delete them is to navigate to /System/Library/Extensions/, then locate the file IOSerialFamily.kext. Control-click (or right-click) on this file, and select "Show Pacakge contents."