2.02 didn't change this. I think 2.02 was really just an emergency bug fix that only fixed a very few select problems. I think 2.10 is where we MAY see improvement if at all.
As far as I can tell, to keep sounds up you have to do two things: 1) FIRST, make sure the ipod volume is all the way up. 2) SECOND, go in to settings>sounds, and turn your sound settings all the way up. Do not use the volume rocker buttons on the side (or it won't take the settings.) 3) Once the first two are all the way up, you can change the ringer volume with side rocker/volume buttons. I'm not really sure if sounds follow the ringer volume or not, but you have to turn them up in those other two place respectively in that order or they will limit each other.
The iPod volume seem to override other settings and turn them down, but if it's up, the sound settings are allowed to be louder.
I think this may be fixed with the 2.1 upgrade. Since upgrading Friday morning I haven't had to adjust my ringer volume and it's now Sunday morning. I've made calls, listened to music, received voicemail, watched videos all without the ringer volume randomly resetting.