I just wanted to say a big thank you to Andrew and everyone who has posted helpful fixes etc on this thread.

Today I successfully installed this mod, with one minor hiccup that this thread helped me address. In my case the mod accepted any entry as valid on all pages except "create account".

@AmandaGero - I don't know if you have resolved your problem or not but you seem to have the exact opposite of me so I was thinking it might be the same cause. The reason for me was that I had named my old header_php files as header_php_save. I deleted these and now everything works as intended.