Compare email addresses without case sensitivity when extending forms
It seems that people are not always consistent about capitalizing email addresses - had a case where someone capitalized an address at form creation time and was then unable to extend it because they used the lowercase form of the address. Although technically local parts of email addresses should be treated as case sensitive I think the chances of a case-only difference being due to a typo are far higher than the chances of having two people registering at once whose email addresses differ only n case.