[Plugin: WP Touch] Pixelated Smiley image in comment BOX ?!

I added the “Smile Themer Toolbar”, “Comment Rating” Plugins in my WPTouch powered blog. All images icons displayed in the comment box would be enlarged ( > 100% of the original size), so all become pixelated.

Since everything back to normal when I view my blog in a PC (not using the mobile mode) and I’ve also tried using other Plugins to add smiley in comment, the same problem appeared. I guess the problem lie in the WPTouch ‘s COMMENT.PHP or .CSS Could you please tell me how to fix this problem ?

This problem only exists in the comment box, the Smiley icons are all normal in the POST body.

SCREENSHOT ~~>