Tinypic randomly does not load

Tinypic.com and images linked from Tinypic (ie., i53.tinypic.com/*) randomly will not load and it is only this site that I have trouble with. This is especially apparent on forums that use these images as icons/signatures and will show a blank box that never loads. If I refresh or return to the page it will sometimes load.

This occurs in both IE9 and FireFox 5 (with and without add-ons enabled) and began within the last month or so. Other computers on my home network continue to load Tinypic and it's images just fine, so it doesn't appear to be related to ISP or my router. If I use a proxy service (ie., TheNinjaProxy.com) and go to any tinypic site it loads perfectly fine 100% of the time.

Based on my Google searching on this problem I have tried disabling my Comodo and Windows firewalls as well as my router (ASUS RT-N16) firewall. I use Avast AV and disabled it completely. Jumbo Frames on my network adapter was and is still disabled. I have tried connecting through Google's Public DNS. Cleared cache, flushed DNS. Changed several settings that I don't even remember in about:config in Firefox (although it doesn't appear to be specific to the browser). I have run a tracert to tinypic.com, and did not receive any timeouts (though I don't really know how to interpret the results aside from that), pinged the specific site that I'm having problems with at the time (ie., i53.tinypic.com) and it reports a 0% loss. I even reset my hosts file to it's default settings and it's not blocked through Firefox image settings (again, doesn't seem like it's FireFox's fault anyway).

I'm out of ideas and I hope someone here has some! The thing that seems like it could point me in the right direction is that it works through the proxy service. What would cause it to work there but not when I try to connect regularly? Any other tests that could lead me to the right answer? Hours of searching and trying random things I've found on Google haven't gotten me anywhere yet.

Thanks in advance for any help!