Heavy Media Keynote files corrupting - help!

Running an iMac on 10.6.8 and Keynote '09.

Having real problems with a keynote presentation which includes lots of photos, audio and high res video.

It seems once the presentation hits 8GB it all starts to go horribly wrong!

When saving keynote takes ages 10 minutes+, and then not saving, but crashing, and eventually it lost all the media from the show, photos, audio and video.

Using .mp3, .aiff, & .mov

Presnetation had 136 slides and included 7 x 2 to 7 minute videos.

Any thoughts? Am I doing somehting wrong or is this just the limit of what keynote can do?