We also ran into this issue and I finally got to the bottom of it. We recently (since May 2014) had three jumps in Issue IDs.
3385 -> 4385
4442 -> 5440
5476 -> 6475
It turns out this is because we migrated to SQL Server 2012. This is a new "feature". This forum post "Primary key auto incrementing by 1000 instead of 1" informed me that when SQL Server 2012 restarts it skips/jumps Identities ahead. See: Failover or Restart Results in Reseed of Identity. Apparently this was on purpose and is not going away.
The quick fix is to add a -t272 startup parameter to SQL Serve. This walk through shows how but it incorrectly shows a capital T and that will not work. Again, you must use "-t272" not"-T272".
The long term fix would be to not use the primary key/identity as the Issue Id. To help with this MS finally added sequences to SQL 2012 and they have a NO CACHE option to prevent this specific behavior. Of course, if you are going to support older versions of SQL Server things get more complicated.
MS FAIL
3385 -> 4385
4442 -> 5440
5476 -> 6475
It turns out this is because we migrated to SQL Server 2012. This is a new "feature". This forum post "Primary key auto incrementing by 1000 instead of 1" informed me that when SQL Server 2012 restarts it skips/jumps Identities ahead. See: Failover or Restart Results in Reseed of Identity. Apparently this was on purpose and is not going away.
The quick fix is to add a -t272 startup parameter to SQL Serve. This walk through shows how but it incorrectly shows a capital T and that will not work. Again, you must use "-t272" not"-T272".
The long term fix would be to not use the primary key/identity as the Issue Id. To help with this MS finally added sequences to SQL 2012 and they have a NO CACHE option to prevent this specific behavior. Of course, if you are going to support older versions of SQL Server things get more complicated.
MS FAIL