Audio in iMovie not fading out properly when viewing in full screen mode

Computer is a 27" iMac, i7 processor, 2 terrabyte HD and 4 gig ram. Purchased brand new in December of 2010, guessing I have iMovie 2011? Spent 5 hours editing a video and everything was working perfectly. Go to finalize and it gives me an error message "not enough memory in the heap file". I restart computer, install some updates and the message goes away.

After finalizing, the music doesn't fade completely out when playing in full screen mode. I check my edits and the ducking is checked and it actually fades properly in the small screen edit mode. Full screen is quirky though, sometimes it fades properly, other times it doesn't. Any idea what's going on?

I'm a bit frustrated as we spent a LOT of money on this thing to hopefully eliminate these frustrating bugs I've had in the past editing on a slow PC. Now I'm running into the same thing. Your help is appreciated!

I should also note, the music does fade but not to the level I specified. I have it fading down to a level 1 but it seems like it's only fading down to maybe 50%. (it's far too loud) Again, if I'm viewing on the small edit screen it works perfectly, this is only in full screen mode.

Anyone? I'm really at a loss here.

Another problem I just discovered is that for some reason the music isn't quite as loud in the second half of the video. So the first minute music is at the appropriate volume. (lets say 100%), then I duck it down to you can hear some dialogue for a minute. Then, I bring back the music for the last minute but the music is at about 80% volume. I checked all my settings in the inspector window and they're all consistent. I even pulled down the audio graph and it all looks consistent too.

Any idea how to fix these issues? Here's the video in question: More Stryker Combat 6-30-11 on Vimeo

Any ideas guys? I'm really at a loss on this one.

If you have iMovie11, you can adjust the volume better than using the Inspector and the ducking tool. in iMovie Help, enter audio volume and then look at the "Adjust the volume of a portion of an audio or a video clip" topic.