1999 B4 Tiptronic problems

I had major problems yesterday with my 1999 B4 fitted with 4EAT
Tiptronic. I haven't had the car long and have noticed what I thought
were just a few quirks with the transmission. One has been discussed
extensively here and that is the high revving in auto mode as it
changes between 2nd and 3rd sometimes. My other problem I've seen
nothing written about. Often when in manual tiptronic mode when the
revs drop and the expected downshift doesn't happen I manually chop it
back a gear. Now sometimes as I do this the Titronic decides it will
chop down also resulting in the car chopping down 2 gears instead of
the required 1. I thought this was just a quirk in the trannie but as
no one else seems to have written about it is it a fault in my
transmission. It really caught me out yesterday. I was coming down a
steep hill I know well in 3rd around some tight curves and as I come
out of the corner with low revs I chopped down to second and gave it a
little gas. At the same time it had automatically downshifted so
instead of 2nd it had downshifted to first. This all happened in an
instance and as I fed a little gas expecting to be in second the revs
screamed as I was in first and full turbo boost kicked in. The result
was the rear of the car come around a full 180. Is it usual for
Titronic to downshift at the same time as I manually downshift causing
it to chop down 2 gears or is this another problem with the 1999 4EAT.
Also can someone explain why the arse come round at only medium speed?
I'm wondering as I was going down a steep hill and it downshifted 2
gears to from 3rd to 1st and full boost kicked in could the LSD have
locked up for an instant. That is what it felt like. It all happened
in reasonably slow motion according to 2 people who watched it but it
felt rather quick to me