Another code conundrum

Calling you lovely coders,

I am wondering why the following shows up via firebug on my site:

img {
background-color: #FFFF00;
}

.profile_pic {
border: 1px solid #000000 ! important;
}
The top one giving me a yellow rim around all my images
The bottom doing nothing (I’d wanted to deselect the header image)
When the first part of the code isn’t in my editor (I removed it days ago) and the following ISNT being read:
img {
padding:1px
border:1px solid #021a40;
background-color:#ff0;
}
(I’d wanted to put a lovely border around chosen images)

:/