I too was having a problem with that error and I called and the lady told me it was because someone else was buying tickets for the same price at the same time and there was a price change. That was not the fact because I tried multiple times and 6 days later, it was the same price.

I am glad I found your post, Keegan, because it worked. Although I had a credit, and I could not use it, I am a frequent flyer on JetBlue and I hope they solve this problem soon, so I can use it.

I sent an email to JetBlue to inform them, and hopefully the person who reads it isn't as inept as an office full of monkeys and they can show it to someone who would actually do something about it.