This morning I made a change to two tables in my live system. All I did was add a new column in each called 'suspense' with a data type of bit and a default value of '0'.
When the users started using the system they noticed that the record ID numbers had reset and were starting from 1 and going up 2, 3, 4 etc. The last good id number was about 20500. The id columns are set as primary key with identity and increment of 1.
This shouldn't happen should it? Is it a bug? I never touched the ID column, just added the new one.
I bet you made the change using Enterprise Mangler. EM tends to make these changes not with a simple alter table add column, but with a drop and re-create of the table. You can try running DBCC CHECKIDENT(table) on the table, which should reset the identity column nicely.