Just something weird that I ran into and thought I'd mention it...
Here's the weird part: if the name of the text input starts with a number, it doesn't work, but, if the input text name starts with a letter, it works fine!!!!!
For example, if I name the text input "sub_10001000" it works fine, but if I name it "1sub_10001000" it doesn't work! What a pain to figure this out when I wanted to use numeric product ID's for names!
Wanna see it in action check the page below. Validated! In the first line the name starts with a letter; in the second, I just copied and pasted the row and added "1" in front of the input-text name:
Tested in FireFox 18.104.22.168 and Konqueror 3.5.7: Exact same behavior.