I've built a form for front-end submission of a custom post type. The form takes a title, excerpt, body, and category (drop down). I'm using the Gravity Forms + Custom Post Types plugin, although I don't think that's related to this issue.
When I try to set a category that has a colon in its name (e.g. "Day: Windy"), the category is not saved. Choose a category without the colon or use a hyphen in its place (Day - Windy) and it works fine.
This is easy to work around, but it took me quite a while just to figure out what was going on. If possible, a fix to this issue would be great!