This is just a short note for anyone else that has encountered this most annoying trait in Quicksilver.
I started using Quicksilver to select the songs I wanted to play recently instead of dropping into iTunes itself (I’ve been using it to play/pause and move to the next song for some time). The ability to browse you’re library via the iTunes icon is very cool (and even better is setting up a trigger for Search by Artist), but it had one annoying trait: when I wanted to play a whole album, it set up the playlist in a seemingly random order. I say random because I couldn’t figure out why it had chosen the order it had, but it used the same order every time. My best guess is that it is something to do with the order on the filesystem.
I tried fiddling with lots of different options, and saw a number of people in the forums complaining about similar but slightly different problems. It’s surprising to me that not a lot of people seem to play whole albums in track order any more 🙂
The option that ended up fixing it was the one I least suspected: under preferences, in the iTunes tab, make sure "Fast Browser Play (less accurate)" is checked. Albums will then play in the correct order.
Now the only thing left to figure out is how playing albums in correct track order might be considered "less accurate"…