Identity is not and never has been guaranteed to be without gaps. Hence the presence of such gaps it to be expected.
If the service is restarting, you probably want to find out why. Check your error logs to see if it is.
Again, is this SQL Server 2012?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability