what's changed is, if you move that guy to the middle of your roster and the guy you want to drop to the bottom and click 'save your lineup'...it doesn't save it where you want him to save and the guy you moved is back to where he was.

Your lineup is now frozen with the 13th guy (waiver pickup) stuck in the middle and whomever you had at the bottom moved back to where he was. In essence, your lineup stays the same, the new guy is placed in the middle of it (positionally appropriate) and now the last guy in your prior lineup is set to be cut at the deadline (instead of whom you tried to manually place at the bottom).

So you have to drop a guy to really adjust the roster otherwise the glitch in the system will fuck you over.

So:
G - Rondo
G - Curry
F - Melo
F - Parker
C - Noah
...
...
G - Holdover Scrub
...
CF - P. Gasol
G - Westbrook <--Claimed off waivers = #13 on roster.

you go to change the line up to look like this:
G - Rondo
G - Curry
F - Melo
F - Parker
C - Noah
...
...
G - Westbrook
...
CF - P. Gasol
G - Holdover Scrub

You click save expecting Holdover Scrub to fall off your roster but the glitch is...this happens instead.

G - Rondo
G - Curry
G - Westbrook
F - Melo
F - Parker
C - Noah
...
...
G - Holdover Scrub
...
CF - P. Gasol <--now in slot 13 and will be dropped at the deadline.

So you now HAVE to drop holdover scrub as the save feature won't do it for you correctly if you adjust the lineup.