I'm actually using WP3.0.3 with Next Gen 1.7.2
It appears that you can now only have 50 images in a gallery or perhaps i'm missing something in the new version. Anything under 50 images, no problem. As soon as I have more than 50 images the gallery page shows a blank page with just the page header.
I've deleted all images, uploaded them individually to see if it was a file causing the problem but it's not and I have tried uploading as a zip file. It all uploads fine, shows in the manage console that there are 146 images but it just fails to show anything on the page.