Thumbnails

To whom this may concern,
Hello my name is Mark Kwan and I run the http://www.Sonicorp.ca  website, my questions are that thumbnails in the metro grid at the top are being cropped to fill in the whole squares they are in, all the correct cropping codes are in place. My second question is, that the thumbnails below the metro grid beside each blog post, they’re are coming out pixelated and not crisp and clear. Wondering if you guys know of any solutions to fix these 2 problems of my website.
 
Thanks,
Mark of Sonicorp