Software you can see when you are in LiveTV and press menu, it should be on bottom of the menu. 5.0.xxx
Do you have your box set for shutdown, suspend, or do you use HDMI-CEC to turn on/off with TV ? I personally prefer shutdown. May take an extra minute to boot up, but it is a clean boot each and every time.
What nbs says is exactly what I have on all my buzz boxes also. IF I am watching a channel which is in my favorites.. Then I shutdown. Then turn box back on again, it will be on that same channel, and if I hit guide, I will see the guide for favorites.
Let's try this as a test. Turn on TV. Turn on the B5. Go to a channel in your favorites. Press CH+ a d few times to go through some of your channels which are in your favorites. Check if Guide brings up favorites. If so, select a channel and change to a channel. OK, not you know that guide is on your favorites, and CH+/CH- cycles through your favorites. Now, hit the power button on the B5 box alone to turn it off (leave the TV on) . Once it is off, go ahead and power it back on. Do you see the buzz animated logo, or does it power up immediately ? OK, go into LiveTV. Then hit the Guide button (or technically you can just hit the guide button from the home screen). Are you on favorites or all ? I tried it on 3 of my boxes and I am always on favorites (since that was the last group I was in).