Don't blame the board for your inept cropping and resizing ability. It's not hard: pick the largest dimension and scale that proportionally using any number of tools (Photoshop, Irfanview, Imagemagick, etc.). 800x600 is perfect for all images that should be posted on the board. Anything more means you haven't done a proper cropping/resizing job.
I'm with MoonShadow.
I've never understood why I can post a 640x480 photo, but not a 480x640 one.
The actual implication is that the same photo will upload fine if shot in landscape, but not in portrait, even though the pixel dimensions and bit sizes are identical.
In what world is a 480x640 portrait orientation photo not appropriate for upload?