Custom icons small on iPhone 4?

Anyone know why some of my icons look small (Safari, Mail, iPod)? The png files are far bigger than the Phone icon (143-356 kb compared to 16 kb) but the phone icon looks fine and the others look off. The Phone icon is 500x500 and the others are 512x512. I resized the icons to 120x120 as well as 114x114 but that didn't do the trick.

I tried changing icon size in CS5 to 118x120 to see if that would make a difference, but it wouldn't let me make the height and width different (if I made height 118, width changed to 118, and vice versa).

Any help is MUCH appreciated!

 

You're spot on.

Can I remove the transparent border to make them full size? Is it that easy? I do have the PSD and PNG of the files.