User uid incrementing in non sequential manner I have a drupal site that has been running for about 1 year. there are about 1000 members in the users table

recently I have noticed something very strange the Users uid field is no longer inrementing sequentially. 

It now jumps up in the 10s, for example, my last 8 users, the uids went from 7999 to 8068, 8094, 8350, 8416, 8458, 8534, 8566. 

So sometimes it is jumping 100s at a time. 

How can I work out what might be causing this, and should I be worried?
If it is exactly 10 then it might have to do with MySQL's Auto Increment value
https://stackoverflow.com/questions/1686327/change-the-step-auto-increment-fields-increment-by

drupal.org currently uses this feature for master slave replication. Right now all users and nodes being created have a odd value. If you look further back this value was EVEN at one point.