I am using Vegas Pro 9.0 and have rendered my customers videos in MP4 format. They all play great on my Windows 7 machine.

However my customer uses Macs and when they play the file all they get is audio.

What HD settings should I render my video files in that works for Macs and PCs. I tried Quicktime but found the quality grainy. Maybe I don't have my settings correct since I am new to Vegas Pro.

Please help