"Info at xyzsite dot ru" writes that Internet Explorer does not correctly handle cookies whose domain contains an underscore character.
However, There's a good reason for this apparently faulty behavior: the underscore character is forbidden in DNS names. RFC 3696 says:
"The labels ... that make up a domain name must consist of only the ASCII alphabetic and numeric characters, plus the hyphen. No other symbols or punctuation characters are permitted, nor is blank space."
If the underscore works in Mozilla or other browsers, it's only because they are being lenient in the validation of domain names.
