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).
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.