ITunes store won't load. The progress bar freezes at about 50% and I get nothing but a white screen.

Question

I'm running iTunes 10.5 beta 7 but this issue has been happening since I was running 9.  One day I clicked on a link for an app I saw on techcrunch and it pulled up in iTunes as being in the UK store.  I clicked ok and my iTunes hasn't worked since.  I can log into my account but can't access anything in the store or Ping.  I've googled this issue and found some similar sounding stories but none of the solutions have worked.  I've uninstalled and reinstalled, turned of the itunes store in parental settings and checked "except for iTunes U", I've uninstalled apple aplication suport and installed safari and every other option I have found and nothing has worked.
Sometimes if I let it sit long enough what looks like an unstyled version of the store comes up but is completely unusable.
Just to be clear, this has been happening since before I was running any beta software or OS.
Any help would be greatly appreciated.

Answer 1

Thank you gchin.
I emailed apple support and they got back to me, I did what he said and it's fixed! SOLUTION found- see below.
I said:
"I can't access the iTunes Store. When I click on it the progress bar stops at 50% and I'm left with a blank white screen (no error msg). I have uninstalled and reinstalled, run the iTunes diagnostics (it said all was ok), gone through all of the online help material and I've tried turning off my firewall. Nothing works. I can't sync my iphone either (stops on verifying iPhone so I think it's getting stuck on trying to contact the store). Plzz help."
They replied:
"Greetings from Apple iTunes Store Customer Support! I am ########.
I understand that you have had issues accessing the iTunes Store. I know how eager you are to have this issue resolved. I will certainly assist you.
#########, for this, I recommend that you attempt to resolve this issue by once again uninstalling iTunes and QuickTime, and then reinstalling the latest version of each. To do this, first ensure that you are logged in to an Administrator user account on your computer, then follow the instructions in the appropriate article:
Removing and reinstalling iTunes, QuickTime, and other software components for Windows Vista:
http://support.apple.com/kb/HT1923
Note: Titles you purchased from the iTunes Store or imported from CDs are saved in your iTunes folder by default and are not deleted by uninstalling iTunes. Backing up your iTunes Library regularly is recommended.
After successfully uninstalling iTunes and QuickTime, please ensure you have upgraded to the latest Service Pack for Windows by installing all updates available to you on Microsoft Windows Update:
http://update.microsoft.com
Once you have the latest Service Pack for Windows installed, download and install iTunes for Windows (which includes QuickTime):
http://www.apple.com/itunes/download
If you continue to experience difficulty with this issue, you may wish to contact Apple technical support. A representative will be able to tell you about Apple's complimentary and fee-based support options and can help you determine which option might be most helpful.
Please find the appropriate phone number here:
http://www.apple.com/support/contact/phone_contacts.html
Thank you for contacting iTunes Store Support. Have a nice day!
Sincerely,"
AND IT WORKED happy customer.