Change Tracking in SQL 2012 - Behavior Change

Hi,
We observed some change in behavior for Change Tracking feature in SQL 2012 Express. Sequence is as follows,
CT is not enabled at DB level. (Of course at table level too)Created and populated table CTTEST with some rows, say 10 rowsEnabled CT at DB levelEnable CT for table CTTESTQueried change tracking data, using change table function (select CT.* from CHANGETABLE(changes CTTEST, 0) CT). No rows returned. Perfect.Updated few existing rowsQueried change tracking data using CHANGETABLE function as above. Now it returns the modified records. But SYS_CHANGE_OPERATION column shows as 'U', indicating update. Same scenario was tested in SQL 2008 Express, and we got SYS_CHANGE_OPERATION column as 'I', indicating as Insert. Is this a change in behavior? Can somebody clarify this? Note: SQL Version is, "Microsoft SQL Server 2012 - 11.0.2100.60 (X64) Express Edition  ( ...