I am experiencing the same problem with a new 955. This is a replacement of, a replacement, of a replacement 950 which died with the old No Sim / Bad Sim card problem - all of these have gone the same way.
Although that is a gripe I have. The problem is as both of these users have stated. Seems to be a growing problem.
I updated FW to latest 6.08.5 from 6.05.??
Any ideas on how to get this working?