I had this problem too and I was procrastinating, hoping it would go away. But it didn't. So after a quick search today, I learned this is an issue that primarily affects us Mac users. I'm not sure how wide spread the issue is for Mac users, but so far it seems most common among OS 10.5.8 with Safari 5.
The good news is that I found a suggestion that worked for me even though I made some missteps along the way. I'll include my missteps just in case they turned out to have played a crucial role in setting up the final step.
- Emptying Safari's cache
- Removing cookies - I limited this to just the search results of [msn] and [.live.] because I didn't want to part with more cookies than necessary. I'm usually pretty selective with cookies, the cookies I keep tend to be because they are a convenience.
At this point my Inbox was starting to work for me. After logging out/in and reloading/refreshing the page, the appearance was largely restored. Unfortunately I still couldn't navigate through folders or emails themselves. But then came my eureka moment.. I had read a thread wherein "msn.com user portland" said that disabling the setting to require HTTPS fixed everything for him. And my limited navigation was now able to access those settings!
- Click the "Options" link
- Click the "More Options…" link (inside drop down menu of previous step, if page isn't totally broken)
- Click the "Advanced privacy settings" link (under the category of "Customizing Hotmail")
- Click the "Go to HTTPS settings" (under the category of "Using HTTPS for extra security")
- Re-enter password (this may not be asked if you recently entered a password)
- Select the "Don't use HTTPS when I sign in to Hotmail" radio button
- Make sure to click the "Save" icon
Done - I was automatically redirected back to the Hotmail Inbox. I reloaded/refreshed the page just to be thorough, and everything has worked normally for the past several hours.
BTW: Disabling HTTPS may not be ideal for people using public wifi networks, but I've had success with VPNs in similar situations where HTTPS was simply not available.