It does something odd with reloading -- it does NOT do the same thing as actually hitting "Reload" on a page. For example: I log in to a site. The site takes me to login.php to authenticate, then sends a 303 header and redirects me to the front page of the site. Because of the 303, hitting Reload will reload the front page; but this login ignores the fact that a 303 was sent, and tries to reload the login.php file (which fails). Give the plugin a better understanding of HTTP headers and it'll be gold; but as of now it's not quite there.
UPDATE: No... it's even weirder than that. It's "reloading" the target of an iframe, I think(?). Whatever the case, it's not doing what it should do, which is reload the page exactly the same as if I'd hit ctrl-r