Upload & Sell: Off
PM email notifications seem to currently be working for me (as of this morning). You can also check the headers on the PM notification email that you received late: you may be able to tell from the timestamps in the "Received" headers (which indicate the path of intermediate mail servers between the sender and you) whether there was a delay elsewhere in the system after the notification email got sent. Sometimes emails can get "stuck" for a while en-route to their destination.
For example, here are some headers from the PM notification I got this morning:
Received: by 10.194.20.106 with SMTP id m10csp98504wje; Tue, 4 Jun 2013 10:00:16 -0700 (PDT)
Received: from webdatabase.fredmiranda.com (webdatabase.fredmiranda.com. [18.104.22.168]) by mx.google.com with ESMTP id rl1si15420396pbc.24.2013.06.04.10.00.15; Tue, 04 Jun 2013 10:00:15 -0700 (PDT)
Received: by webdatabase.fredmiranda.com (Postfix, from userid 502) id 010CC1087C11; Tue, 4 Jun 2013 12:00:14 -0500 (CDT)
So, appearing in reverse order by time, the message passed through FM's "webdatabase.fredmiranda.com" server at 10:00:14 in the morning (Pacific time zone), then was received by Google's "mx.google.com" server at 10:00:15, and passed along to another mail server (probably something internal in gmail) at 10:00:16. From this, you may be able to tell where the delay occurred.