I'm not very familiar with the Elite either, but there must be a "transfer to the voicemail" of ext. xxx rather than a simple transfer to the station. In many systems, when they fail to see a device connected to the port, they act as if that extension is non-exsistant when you try to transfer directly to it. In this case, you would need to use the keys sequence to transfer directly to voicemail.

"I'm the one that has to die when it's time for me to die, so let me live my life, the way I want to."
-- Jimi Hendrix