Skype Connect SIP registration

I sucessfuly managed to connect my asterisk box to skype connect. My config below:

here is my sip.conf:

[code] [general]
context=from-skype ; Default context for incoming calls
allowoverlap=no
udpbindaddr=0.0.0.0
tcpenable=no ; Enable server for incoming TCP connections (default is no)
tcpbindaddr=0.0.0.0
srvlookup=yes
allow=all
dtmfmode=rfc2833
port=5060
register => 9905100xxxxxxx:xxxxxxxxxx@sip.skype.com/9905100xxxxxxxxx
trustrpid=no
sendrpid=yes

[9905100xxxxxxxx]
fromdomain=sip.skype.com
username=9905100xxxxxxx
fromuser=9905100xxxxxxx
secret=xxxxxxxxxxxxxx
realm=sip.skype.com
host=sip.skype.com
type=peer
dtmfmode=rfc2833
qualify=yes
context=from-skype
nat=no
canreinvite = no
insecure = invite
disallow = all
allow = alaw
allow = ulaw
;allow = g729 ; Uncomment this if you have G729 licences
amaflags = default
trustrpid = no
sendrpid = yes

[/code]
Sometimes I get ‘User busy’ when calling from mobile or ‘user not found’ when calling from skype, and sometimes it just works. When I cannot connect I do not get any output to asterisk CLI but I get log in skype manager that call was forwarded.
All I could figure out it’s that my asterisk is not succesfuly registered to Skype at time of call.
Sometimes I get in CLI:

[Jan 18 12:20:14] NOTICE[16200]: chan_sip.c:12707 sip_reg_timeout: -- Registration for '9905100xxxxxxxx@sip.skype.com' timed out, trying again (Attempt #17) [Jan 18 12:20:14] NOTICE[16200]: chan_sip.c:20084 handle_response_register: Failed to authenticate on REGISTER to '9905100xxxxxxx@sip.skype.com' (Tries 3)
but most of times nothing.
When I switch on debug on sip I always get successful response and I’m able to make calls.
Please Help