1)
I'm on an iMac, and the screen is pretty bright in the evening, and the gray dotted signature and submitted borders are barely visible to my eyes. There may be more lines, but I cannot see them.
.author-signature { /* style.css (line 132) */
border-top:1px dotted #DEDEDE;
margin:1em 0pt;
}
.submitted { /* style.css (line 144) */
border-bottom:1px dotted #CCCCCC;
color:#333333;
font-style:italic;
}
Running into the signatures often confuses me while trying to understand the posted material. I'd suggest solid black borders.
2)
The topic's #forum h1.title does not have any visible margin that would separate it from the advertisement above. I'd suggest more vertical spacing in general.
3)
I find the *{;} default avatars distracting: I tend to think that it is the same person, even if I try hard to look at the name. I'd suggest to turn this off.
Sorry if this has been covered to death. I would like to concentrate on the content, and the current layout does not serve this well.