acomdata hard drive not showing up on finder

Hi everyone,

3 weeks back I had purchased an Acomdata external HD 500gb. But last night, after I had ejected the drive from the G5 and mounted it on to my macbookpro, it would not show up on the finder.

I immediately put it back on the G5 but it did not show up on the finder of that one either. Its not recognized by disk utility either.

I am a bit panicked since I have to reshoot all the footage as I had used P2 cards to shoot the film and saved them here. And this will be a killer.

I'll appreciate any help regarding this. Is there any chance of retrieving the data stored here?

Thanks for all your help guys.