What's up with Fitday? When I click on a link, for example to search a food or to recalculate values, I get a page that says "Found The document is here". The word "here" is a link which takes me where I want to go. It's annoying to have to make the extra clicks.
Using fitday in Firefox does seem glitchy to me. I didn't experience what you did. However, my foods disappeared for awhile and then suddenly reappeared - my food tally for the day so far. Don't know why that happened or if it happens to other people. Chrome does seem to work better for me.