YoVille will NEVER ask for your password, so please be wary of malicious emails and/or forum posts that request your password, including via web links.
According to the announcement anyone who logged in during the gem event that was missed for many would be compensated with 490 gems and 40 points (equivalent to a 4.5+ reward). I have not received either reward and was certainly logged in. How long will it take before the gems are given out? Is this yet another bug?