I had a similar experience with my current employer during the interview stages.

1. 30 min technical telephone interview with direct line manager

2. 30 min face to face with direct line manager and division director

3. 1 hour technical phone interview with the VP, I was not expecting yet another technical interview and the questions were exceptionally tough and looking for real indepth sql server knowlege, he was a very intelligent guy that has since moved on.

4. 30 min general interview with the CTO, general discussion about my past, experience, what I could bring to the company etc etc. Quite repetitive from the previous stages. This seemed much more like an assesment of whether my personality would fit within the team and the wider organsiation, once I started I found out that the last interview was pretty much a formailty as the decision had been 99% made.