I haven't had any other issues with it... it seems more stable than prior versions for me.
Busy box is just a small set of *NIX command line utilities, I don't think MIUI has ever included it. You can install it from the market though.
I'm running 2.3.30 on a G2 (Desire Z), and I'm not sure if this is version specific or platform specific so I'm posting here.
I have run MIUI in the past but tried a few other ROMs and now I'm back to MIUI (it's the best!). For some reason in this version I cannot get anti-stranger mode to...