internet explorer problem

[SusantheMartian]

one problem is that my site is created with using firefox as the web browser so it looks pretty decent in ff, but when i view it in internet explorer, everything isnt positioned right. my website is here (http://koportal.com/mac/) and if you go to the video section (media -> videos) even in firefox, the 'site' header gets a bit mispositioned. i think it has something to do with the tables that i use to make the videos on the site but i dont know how i can fix it without messing the rest of the pages up because that is apart of the php include for the sidebar. can someone please help me with this.

[_Aerospace_Eng_]

You have 265 errors in your coding and 46 warnings. You can't expect a site to display properly with that many errors. See your errors here (http://validator.w3.org/check?uri=http%3A%2F%2Fkoportal.com%2Fmac%2Fvideos.php&charset=(detect+automatically)&doctype=Inline&ss=1&group=0&user-agent=W3C_Validator%2F1.591).

[SusantheMartian]

i guess fixing those would be a good place to start. thanks :)