... I finally found the issue...
I'm guessing a date range set to 'yesterday' - which gives me a chance to mention (for the benefit of newer advertisers in particular) that the date range setting is 'sticky' and will stay where you put it, until you actively change it again.
I always advise making a habit of checking the date range to which one's stats are set, first thing upon logging in.
In any case, whether or not this was the issue, SeoMasta, I'm glad to hear that things are operating smoothly now. ;)
AWA