OK, I found a solution to my problem, but since I had to comb a LOT of message boards to find it, I thought I'd repost it here. Here's a link to the message board that gave me the answer:
http://gotdotnet.com/Community/MessageBoard/Thread.aspx?id=9412
Basically, Visual Studio designer deleted the entire body of the initializeComponents method, including the all-important line
this.Load += new System.EventHandler(this.Page_Load)
That left my page entirely useless. I have no idea why the IDE decided to perform this useful task for me, but in case it ever chooses to help you out in the same way, just paste the above event handler back in.