Wrong data retrieval from list during edit mode

I have custom web part, which in edit mode retrieves Name/Title from different list than it should (other values are correct). Somehow it retrieves current pages (from pages library) title instead of list items title. The other quirk is that if I checkout before entering edit mode - it works as it should. Sorry I can't provide code for analysis, but would be grateful if someone could provide any suggestions for such behavior.