Job interview: what do you guys think?

I went for a job interview with a technical college on Friday, March 18th. There were four interviewers, and they had split up 15 questions between them to ask me. I don't remember what the questions all were but it was very typical interview fodder. What is your biggest strength, what's your biggest weakness, what do you know about our college, why do you think you'd be better than anybody else, etc.

I thought I did really well with the interview. I had to trek halfway through the building in heels (which I don't usually wear) to get to the interview conference room, so I was a bit out of breath, and it made me seem incredibly nervous b/c the first thing they did when I got in was to ask me to tell a bit about myself. The second thing going against me was that I remembered the job description as being for an accounting technician, mostly dealing with reconciling student accounts for accounting purposes. I emphasized my ability to use GAAP with keeping the books and such legally. It turns out that the position is more working one-on-one with students by accessing their accounts and answering their questions, so I'm sure I sounded stupid describing how I can help them legally comply with GAAP. I checked the job description later; it was as I had remembered it. Little work with students, mostly emphasis on accounting. So I have no idea what's up with that, but I didn't think it hurt me much.

As soon as they started explaining the interview process to me, I had a chance to catch my breath and I answered the questions very conversationally. Every time I spoke, my interviewers were nodding their heads and verbally agreeing with me. When they asked me to describe a conflicting situation with a coworker, I nailed it and found the perfect balance between whining and thoroughly explaining the issue. They actually laughed when I described it. When it got to the guy who was going to be my supervisor, he actually said that he thought he and I would get along great working together. They seemed very pleased with me, and told me that they already had a direct supervisor hired for this position who would begin April 1st and that they wanted to hurry with filling this position. If I got a second call back, I'd be interviewing with the dean of the college, and they'd let me know.

So I got home and immediately ordered a blazer for the formal second interview. I was that sure I had it. I sent a thank you letter to the head interviewer on Wednesday the 23rd. I wondered why they hadn't called back if they were really moving fast like they said. By Friday, I was convinced they weren't going to call back, but still determined to call and get an official rejection. I called on monday the 28th and they said second interviews had not gone out and a decision hadn't been reached. Now it's Saturday, and I'm wondering, WTF!? I know some places will wait and only give second interviews to those who do call within a specific time frame to see if these people Really want the job enough to call. These people are taking a long while though.

I intend to call back on Monday again to see what the deal is, since you're supposed to wait a week in between contact, but I'm confused here. What are they thinking/doing? Is their lack of response something that I did wrong? I really want this job, and I'm perfectly qualified for it. I have education and experience, even more so with the one-on-one aspect of helping anybody who shows up at my desk with a problem. I thought I did everything right and within the correct time frames. Any insight into what they could be thinking is much appreciated.