1) HQs "leading the charge" or allowing themselves to get way out ahead of their subordinate units, or totally exposed. Happens "a lot" (not often...just often enough to irk me

). Just a few minutes ago, I had an FSJ battalion HQ leading a regimental march and got ahead of the rest of the gang and just about ended up getting killed. See the first example in the "Battalion HQs leading the charge" posting of mine for an OBVIOUS case. The first graphic is the perfect example.
2) assaults which are ordered which do not result in movement (Arjuna mentioned this is a problem occassionally). Kind of a subset of number 6 below.
3) something I call "the lost battalions"... units getting left behind in an advance which are never called up again.
4) Slippage problems (the problem of a FRESH battalion at the beginning of a scenario having an assault time on D2 at 0600 and they are sitting on the FUP, but they insist that they will be four minutes to two hours late even though they are ready and on the FUP and it is 18 hours ahead of schedule)
5) Tonight I caught units not accepting assault time changes at all, even though it was several hours to go before the time I wanted to enter. It would simply not let me change the times.
6) Units not taking orders - having to re-issue orders after waiting 2 full days for action (I caught that tonight as well by CCB6 in the Bastogne Breakout scenario...it's a bit frustrating when you wait 2.5 days for a formation to move to take an objective--I finally broke it into its components to get some use of it).
7) Formations not "launching" at set assault times (not sure this is a serious issue...because maybe they can have a set assault time, and not officially "slip" it, but be too tired to move...in which case it may be a (somewhat confusing) non-issue).
So, I go through a process of
1) pause game
2) give orders
3) create save file with description of which orders were just given
4) keep playing
5) see if something weird/totally wrong happens
6) create report for Arjuna
Basically that is it.
Doesn't mean it isn't the greatest tactical/operational game ever. And these don't happen A LOT. But I want to stamp them out for good.
Though even when playing to catch these errors and not to win, I managed to score a decisive victory in the "Bastogne Breakout" tonight--and think I am about to win as the Germans at St. Lo. It seems micromanaging your artillery is the key to the game.