This excerpt taken from the XIDE DEF 14A filed Jul 24, 2009.
What should I do if I receive multiple Notices of Internet Availability or sets of voting materials?
You may receive more than one Notice of Internet Availability or, if you receive printed materials, set of voting materials, including multiple copies of this proxy statement and multiple proxy cards or voting instruction cards. For example, if you hold your shares in more than one brokerage account, you may receive a separate voting instruction card for each brokerage account in which you hold shares. If you are a stockholder of record and your shares are registered in more than one name, you will receive more than one proxy card. Please complete, sign, date and return each proxy card and voting instruction card that you receive.