Hi Omer,

Thank you for the quick reply.
Is there any data I can collect that might help identify the cause.

Some information I can give you is that when the sms comes in, the N900 somehow identifies this as a special voicemail sms. No sms message shows in conversations. Instead, another entry appears in the phone app instead of the usual up or down arrow, there is a yellow tape icon labeled voicemail. Once you call to get messages, the icon changes to a blue up arrow. Unlike other calls, there is only ever one voicemail entry.