I've had this happen where things just didn't show up in my transactions list, however this was long before you got a hold of game database. I'm sure I didn't help at all, but whatever.

So it wasn't just me that had this problem.

I added one screenshot to Luigi's Mansion and six to Kirby's Air Ride. And received no VG$, I did this on the 1st of August.

July 29th I added a bunch of games and boxarts, and added those screenshots.  The games and boxarts gave me VG$, but the screens didn't.  They went through but don't appear on my transaction history.  It seems kinda random, and pretty rare too.  It's only happened a few times that I've noticed.

Has the view by last updated option been removed?

Excellent job TalonMan

Just noticed something that's really not important but for games that have their name changed. The change isn't being recognized when you view your games. It still shows the old name (the heading on my browser that shows what page i'm on also shows me the old name).