I've been having this really weird issue with my company's CS3 beta. I'm making catalog sheets for them on my MBP, and when I transfer them (in jpg, bmp, png, pdf, etc.) to my work PC, the background opaqued layers disappear (reflections, blur, effects). I have no idea why, as the file shows up fine in OSX Mail but disappears when I load it up in Thunderbird or whatever on my PC. I've even tried taking a screen shot of the image in Preview and sending that file over and that still doesn't show up. Any clue as to why this is happening?