Depending on the error it may or may not make a diffrence as far as IR ( Information Retrevial) in concerned. For instance a missing " in any html tag wont close untill it reaches another ". Which makes it difficult to determine what is html and what it content. The html gets stripped and cleaned out.
The other problem is your domain is only 14 Weeks 6 days old.
I am in a hurry today.
Check out some of the tools here http://www.syllabus.biz and goto seo tools. They will help assist you.
I have a collection of other tools thats good... i dont have them on this computer.