I am gonna try it now and let you know.
Tested, now on classic interface and it doesn't make a difference - it seems that if I have my bag window open and pick up via pressing tab key I can't simply run off clicking right mouse button unless I release and press it second time. I am gonna do some more testing yet
More testing, it is only when I pickup with tab key and then press right mouse button to run off. And it doesn't matter if the bag window is open or closed. If I click just the right button briefly, like only as clicking it to make a step, it works, I make a step to next item (like if you got more items around) but when I press it and hold to run off after tab pickup I don't run, I stay in place till on second try with right mouse button. I will relog on my second char and see if its the same on that one.
OK my nooby warrior is the same, and it is playing in the smaller res, I think 800x600 whereas my sin in 1024x768, so resolution or interface doesn't make a difference.
I throw say three items on ground and then I pick them up with tab key and move from item to item by right mouse button - just clicking it briefly with mouse farther off char as if you wanted to run... that's usually how I go about picking up drops in caves, by moving from item to item using right button briefly pressed, like just clicking it, and it makes your char move one tile. It seems sometimes it works but mostly you need to click second time to move to next item and it hardly ever works when after you picked up last item and want to run away.
So if you had items which are not next to each other but more spaced and you'd want to run to next one, you can't till you release and press the button one more time. Left button works as it should but mostly nobody is using it, we all run and use the right button to move from item to item and pick them up pressing the tab key and when we have picked up what we wanted, we then press the right button again but this time hold it to run away.
At least I think that's how pretty well all of us play? Wonder nobody complained yet. Its a pain in caves when you want to pick items with mobs atacking you, slows you down so much you can get killed. Anyway it is a good policy to move about only using right mouse button because that way if you click on guard you don't get killed or on mob and instead of going to item to pick it up, you move towards targeted mob...