If you use the gmail notifier, it will dump you into a standard http session, not a https session.

@charles
well speed is first reason-google always carefully assembled their websites to achieve fast loading times for to avoid world wide wait

other reason is control over what employees are sending out&receiving. I have been working on MS ISA webmonitor plug-in for 9 years and you would be surprised how many companies sees https as bypass through their gateway security. Gateway products resisted to infiltrate into https and therefore break one of the purpose of https -to protect against man in the middle
attacks. However perception changed and these days gateway products do break https and certificate of website received by browser might not be what web server sent.

btw chat part of https gmail page is in plain http form which is not as secure solution as it should be.

I've had this option enabled since it was first made available. Why anyone would want to access their sensitive e-mails over an unsecure connection is beyond me.