jQuery Cookie plug in behavior is setting domain to com if cookie is session cookie

Question

Folks,

I've found that the jQuery cookie plugin is setting the domain to ".com" if the cookie I'm setting is a session cookie.

Here's the code:

jQuery.cookie("currentTab", selectedTab );

If I look at cookies with IE's Developer Tool, it shows the domain as ".com".

If I set this way:

jQuery.cookie("currentTab", selectedTab, { expires: 1} );

... then it has "www.sitename.com" as the domain.

Is there some trick I'm missing, or have I found a bug?

Thanks.