Asterisk realtime - Subscriber absent

Hi! I am new to asterisk and i don’t know how to resolve following issue:
I have installed asterisk (version:, running on CentOS 6.6) + mysql and connected 5 test phones (D-link dph-150s with lates firmware).
Everything is fine for about 10 minutes - i can call / transfer / pickup and etc. but after +/- 10 minutes all phones become unavailable and i can see following error in asterisk console:

record in db looks like:

id: 23 name: 0405 ipaddr: port: 5060 regseconds: 1429624276 defaultuser: 0405 fullcontact: sip:0405@ regserver: useragent: DLINK DPH-150S FRU2. lastms: 5 host: dynamic type: peer context: all deny: permit: secret: NULL md5secret: NULL remotesecret: NULL transport: NULL dtmfmode: NULL directmedia: NULL nat: no callgroup: 1 pickupgroup: 1 language: ru allow: NULL disallow: NULL insecure: NULL trustrpid: NULL progressinband: NULL promiscredir: NULL useclientcode: NULL accountcode: NULL setvar: NULL callerid: NULL amaflags: NULL callcounter: no busylevel: NULL allowoverlap: NULL allowsubscribe: yes videosupport: NULL maxcallbitrate: NULL rfc2833compensate: NULL mailbox: NULL session-timers: accept session-expires: 0 session-minse: 90 session-refresher: uas t38pt_usertpsource: NULL regexten: NULL fromdomain: NULL fromuser: NULL qualify: yes defaultip: NULL rtptimeout: NULL rtpholdtimeout: NULL sendrpid: NULL outboundproxy: NULL callbackextension: NULL registertrying: NULL timert1: NULL timerb: NULL qualifyfreq: NULL constantssrc: NULL contactpermit: NULL contactdeny: NULL usereqphone: NULL textsupport: NULL faxdetect: NULL buggymwi: NULL auth: NULL fullname:NULL trunkname: NULL cid_number: 0405 callingpres: NULL mohinterpret: NULL mohsuggest: NULL parkinglot: NULL hasvoicemail: NULL subscribemwi: NULL vmexten: NULL autoframing: NULL rtpkeepalive: NULL call-limit: 1 g726nonstandard: NULL ignoresdpversion: NULL allowtransfer: yes dynamic: NULL
Any ideas what can fix this behavior?
Thanks in advance!

The devices have failed to re-register.

Thank you for your reply/
Aww, can you tell me what can be cause of this disgraceful behavior?
I tested this phones on basic installation of asterisk (without realtime) - everything was fine.