I had the same issue and I found that I had in my skin.css:

body {
 text-align: center; }

I used it to center the main div in page. You may have it in the default.css or portal.css as well.

The solution is to use text-align: left in the element that group all other elements in the page under the body.

Also, I think DNN default (if you do not explicitly specify a doc type ) is transitional so why put this in the first place?

Yehuda 

Nope i didnt, ye Quirks and Standard pages are same thats what is confusing me, because on Standard is Standard Compliance Mode and module is aligned, but from that point you have to enter profile from login links (upper right corner where is "test Logout" so click on test and you will see the difference, there are all labels, tips, textboxes, everything centered in its parrent column. Repeat same procedure for Quirks and everything is normal there ...  I asked few friends with different browsers and its safe to say all browsers show same result, IE7, FF 2.0.0.14, friend tried Opera ... So i thing you are just comparing 2 pages, you have to enter that profile from loginlinks to see nonpaged module in action,