You have 3 blank lines in the start of your file before the DOCTYPE. It's giving the [validator.w3.org ] some issues as well as reporting more than a few errors. Ditto for the CSS validator [jigsaw.w3.org ] is reporting more than a few errors.
On Lubuntu 12.10 with Firefox 17.0.1 there is no discrenable difference when flipping from http to https tab. What OS and browser combination were you using? (So I and others can try to reproduce).
Welcome to WebmasterWorld jp12, next time post an extract of your code (per the forum charter linked above).
2:13 pm on Dec 18, 2012 (gmt 0)
The page looks similar to me, but not identical (in Chrome). Using the Developer Tools, I see the following on the https version: [blocked] The page at https://www.qtmarketcenter.com/ ran insecure content from http://yui.yahooapis.com/combo?2.8.1/build/reset-fonts-grids/reset-fonts-grids.css. So you're missing the styles provided by the YUI Grids because you're trying to access them from a secure (https) page via an insecure (http) protocol.