Working on negative decimal input, that little '-' is proving to be pretty difficult to support. O_O
In progress though.

The highlighting... yeah, I noticed that. It only happens when the textbox is full and won't take any more letter input. It's because I check to see if any of them are full, and if they are, I deny any characters from being pressed but allow control characters, so you are able to highlight and backspace when it's full. I'll have to see if I can work around it.

As far as the hex limits go... yeah, that binary box fills up pretty quick. A feature I'm working on is being able to disable the binary box so that you can afford more digits in the other numbers... maybe I'll add a menu for it.

BTW, try resizing yours. :P