Thanks so much everyone! I went through all the core files that had to do with feeds and think it might have been that one of them had uploaded improperly, because though I didn’t find any blank lines, once everything was uploaded again, it did seem to start working. So, for future people who run into this problem, that might fix things for you, too :-).
For me, I was seeing the error both when I clicked the RSS button in Firefox and also when I tried burning the feed in my FeedBurner account.
I’m glad you got yours fixed, too, matrixagent!
Again, thank you so much everyone–I really appreciate the help!
