ZLA Controller described an airspace separation event when an automated hand off was directed to the wrong LAS sector; the reporter alleging these hand off anomalies have increased since the most recent LOA change.

Narrative

I was handing Aircraft X to LAS Approach and noticed that the Data Tag was flashing to what I thought to be the wrong sector; Canyon. I called both Canyon and Lakes; the sector that I thought it should be flashing to; several times. I finally made contact with Lakes and asked them who the aircraft should hand off to and they advised me that it should hand off to the Canyon Sector. I made attempts to contact Canyon with no success and turned Aircraft X away from approach airspace too late to miss their airspace by 2.5 miles. The Controller that was going to relieve me called Las Vegas Approach and told me that Lakes Sector called RADAR and I could turn Aircraft X back in. We have been having a large number of automation issues since the new LOA was implemented. Aircraft often flash at the wrong sector from us to them and from them to us. We do not have accurate map configurations to show who owns what airspace at Approach. Recommendation; automation between the facilities needs to be corrected. Current and accurate airspace configurations need to be provided.