Safari 4 and Chrome show a security error when a Lightstreamer application is in use.
I think that the problem is the same for both browsers (the message is the same and both use webkit so I imagine that's a webkit issue) but while Safari shows the issue even with an ultra-simple test case Chrome doesn't.

The message shown are similar to the followings:
this message suggests that the problem is the communication between two pages coming from different servers, btw such messages appear even related to two pages coming from the same server:
Such message is not completely correct as in both cases the protocols match, the ports match and even the domains match (as domains are set by our javascript library to "").

My hypothesis (confirmed by the previously mentioned test-case only on Safari) is that it is enough that two pages coming from the same server change their domain to something else (eg from to and communicate for the message to be shown.
I have to declare it an hypothesis since the test-case doesn't work with Chrome.
Moreover an application deployed on Lightstreamer server doesn't show the issue on Safari.
So it's not exactly clear what causes the error message.

In any case such messages are harmless and appear only after the first calls so that you can ignore them completely.