I am writing this as I wait for recovery from an XMB crash.
I was playing solo. One song at a time, check the leaderboard before (as I often do), constant switching between both sort modes (in response to another bug, in that it won't remember "Sort By Leaderboard Rank" between songs). Often visiting the options menu, as I turn breakneck speed off for Expert difficulty, but on for Hard.
My BIGGEST difficulty with it isn't that it happens, but that it takes so darned LONG to get back into the game. Why? It has to re-scan every DLC track, EVERY time. I own every PS3 release, including about 80% of RBN (skipping only those without keyboards since RBN 2). It's 1337 items it has to read each time.... and it takes about 3 minutes.
3 minutes? Feh, that's not long, you say. Tell that to online players waiting for you to rejoin the band.