Very true, They are mainly tactical fouls we give away which result in yellows, It's funny though because we get that alot against opportunity and goes unpunished but that's down to the inconsistency of the officials.
I've lost count as sure along with many others being at games finding yourself saying "Is he going to book him yet?" after his 6th foul in 20 minutes! :-)
Yesterday is actually a good example too, Ugarte made a bad foul on the halfway line to try and stop a counter but the ref played advantage and when the game stopped he didn't book Ugarte, Ugarte eventually got booked in the second half and had made 6 fouls (after his yellow) and stayed on the pitch.
It being the best league in the world, The officiating is possibly one of the worst unfortunately.