Shutter speed...?

Question:

Shutter speed...?

Today while taking a few photos, I elected to use full manual so I could control the exposure. Things were fine a first but then I noticed that I couldn't get the shutter to go faster than 200. It's never done this before. I played around with it a while and it suddenly allowed me to go to what ever speed I wanted. Then a little later it did the same thing. I thought about it and can't figure out what happened. Has anyone had a similar experience? Please share!

Additional Details

2 weeks ago
I have a Nikon D80

Best Answer - Chosen by Asker: 2 weeks ago
I have a Nikon D80