you've committed grid blasphemy all throughout this. you have misalignments in everything.

top to bottom:

• your top links look awful. separate from being too cramped, they're right aligned, so they break past the right column into the left, only they don't align to anything. if you left aligned them you'd give them more breathing room and they'd at least be contained to 1 side of the column split.
• the search bar isn't big enough to line up to any specific point in the column - there's no reason not to extent it to either th 50% mark of the right column, or just align with it completely.
• the logo doesn't align to anything either. it's too thin to line up to the 50% line of the left column and it looks too big to line up as a 1/3 alignment. this affects the welcome text.
• while the login aligns with the right column's content, the point on the rss icon throws it off balance because it shows a direct line of sight/ it's also the closer element. the inputs also cut off at another arbitrary alignment. why don't they extend all the way to the edge of the column?
• your advertisement grid is a mess. there should be a consitent margin value around all 4 sides of the boxes. they're spaced equally in relation to each other, but in relation to their surroundings nothing lines up. they should line up with the copy. and the split up the middle should be in line with the 50% line of the right column.
• you're footer just threw the grid right out the window. the body and header look to be aligned in 5ths - 3/5 for the left column, 2/5 for the right. the footer is in 6ths.

everyone hates tables, but honestly the css revolution has thrown up on web design. good structure and layout works within the function of a table. your columns work on rational fractions and everything aligns.

i honestly can't look past the alignment issues to talk about anything else.