*Sigh* I have.
I remember in 6th grade we had to write a story for language arts. I worked very hard on that (3 pages long) and I ended up getting a C. My Spelling grammer with very awful back in 6th grade (better now), thats one of the reasons for my C

This wasn't a project, it was a test. I had been doing poorly in 8th grade algebra and the teacher warned me that if I didn't pass the test I might flunk. So I worked hard, turned in all my schoolwork all week, and studied my ass off for this huge exam. I had a high "D" in the class, so if I passed this test I would have brought it up to a "C" or so. The day of the exam I tried my hardest, and then the following Monday the teacher had our semester grades. She showed me mine and I had failed the test and gotten a low "D" in her class. I started crying right there at my desk because I had really tried my hardest and it still wasn't enough.

If you've ever seen the Simpsons episode "Bart Gets An 'F'", it was almost exactly like that. Except I didn't end up passing. And I had to rot in summer school.

Not that I can remember...but the inverse has happened to me once.

In the sixth grade, I procrastinated on a major math project. I was planning to wake up early the morning it was due, but I overslept and went to school without even starting it. When it was being collected, I told my teacher that I couldn't find it. I was flipping through my binder in front of her, pretending to look for it...she herself was going through my stuff, helping me find my nonexistent project. To my relief she said that I could turn it in the next day. I procrastinated again that night. I was up in the middle of the night working on it. I was rushing and was pretty unsatisfied with my progress. I even cried a couple of times, but I eventually finished it. I ended up getting a 100%.

Not projects, but there were lots of tests I studied really hard for and did poorly on them.