DM4 not recognizing correct file size etc

[deebingo]

I've taken a 4.11 gb project (using 4.7gb media) and created a disc image for it but can't burn it to disc because DM4 tells me the disc dosn't have enough room. I've tried 2 different types of blank 4.7gb media and it says the same thing. For one thing the disc image itself took about 3.5 hours to be created and when I went to check on the actual .iso file (disc image file) it was listed as 6.6 gb.....huh? Why does the interface at the bottom of DM4 say 4.11 gb of info when my disc image is over 6? And why does it take forever to create a disc image? I turned all of my .wmv's and .avi's into mpeg-2 through a converting app. (Winavi) before loading them into the project and have the "do not convert compliant mpeg files" box checked. GSpot indicates that all of the files are mpeg. Any thoughts? I'm stumped...