New to Workgroup PDM

Just got my first taste at workgroup PDM this morning and I'm following the tutorial within Solidworks. I noticed that if I checked out a part from the vault made some changes and check the part back to the vault it still thinks I'm the owner. I have to go and "Release Ownership" for someone else to check out the part to work on it if necessary. I always thought that once you checked in a part in the vault the ownership is automatically released from from that person and anyone else who have permission can check out the part to work in it. Is this not so?

Kris.

SolidworksWorkgroup Pdm