Structure, Narrative, Hierarchy.
I don't know where to look - there's no focus to the page and i'm left trying to take in the whole page at once, while being distracted all over the place.
Maybe tighten it up a bit with more obvious sectioning - make the main window an "upcoming events" section or some such and define the two events more separately so that they don't fight one another (smaller logos perhaps, and a more consistent layout for the two events).
Logos are important to the sponsors but generally no one else - your challenge is to make them as minimal an interference as humanly possible while keeping them happy enough to continue the sponsorship. They will always want them bigger, you should always try to make them smaller.
Likewise with the Support the Foundation screamer - perhaps it too could be in the main window, as a permanent fixture but not lumped in confusingly with the quick links.
Web pages need to read like a story. The eye starts at the top left and scans in a diagonal down to the right, so the information on the page needs to follow a similar flow. Logo (who are they), Statement (what are they about), Main Features (what's important here).
The Main Features need to be able to be scanned at a glance, and structured similarly, with identifiers (what is this) eg "upcoming Events", titles (that are bigger than the supporting details), then the details, in a visual hierarchy, so that viewers can instantly grasp what it is they're looking at and make an informed decision as to what to examine in more detail.
Reading on screen is not easy, so try and make it possible for people to find and read the main points with a quick scan, rather than forcing them to read everything.
Then the user is free to scan the rest of the page to see what else is on offer on the rest of the site (via the nav and sidebar info and links), but already has a instant, firm grounding in why they should bother to make this further effort.
