Yesterday I was reviewing a client data and for events, I found a "ghost" row with a null category/action/label, that was showing 0 total events, and XXXX total unique events. Check the attached screenshot.
Even when you filter your events list by ^$, the row it's there, but the column total sum shows 0, when the row has a value.
If you try to cross that event with any dimension (hostname, browser, ...), it disapears.
If you check the data day by day, either you won't hit this info, or the sum of values by day won't match the total of the same selected period.
It seems to be related to pre-calculated reports, since if you add a yes OR yes segment, this row dissapears. (for example user type = .* ).
This morning I'm founding this in 5 more clients (including premium accounts).
Anyone else noticed this?, is it some processing bug at GA side?