This is a known issue with the Chrome web browser that affects javascript libraries which use this technique for communicating. The Chrome browser issues list has a ticket about this:
When using @Anywhere I get the error message below in Chrome (see, for
example, http://www.fantasy5live.com)
Unsafe JavaScript attempt to access frame with URL https://api.twitter.com/xd_receiver.html
from frame with URL about:blank. Domains, protocols and ports must
match.
I saw a message on this list from about a year ago with the same
problem; is there any update on this?