SMSC with Nokia 6310 and CMS error

Hi,

has anyone tried to set up a SMSC with Nokia 6310? Any experiences? I have a 
configuration with several Nokia 6210 on one Kannel host and it works fine, 
but changing the mobile phone puts me in a lot of trouble. First it seems to 
work fine but after a while (half an hour) the 6310 returns lots of CMS 
errors, most of them are code 301. Doing a restart doesn't really help, 
Kannel wants to establish the connection to the mobile but doesn't success, 
the status is only 'connecting'.

Any help would be appreciated.

By the way: I found a documentation about CMS errors and return code 301 means 
'SMS service of ME reserved', but nor further explanation. What does this 
mean exactly?

Thx in advance
Thorben Hischke