Zoho Mobile Mail Loads very slowly and/or doesn't load

I've bookmarked https://m.zoho.com and use it regularly on my HTC Sensation. In general, I like the mobile site. That being said, I find the initial "dashboard" loads almost immediately (which I love), but drilling down into my unread emails tends to either be very, very slow or it just never loads at all. The symptoms of it not loading are that the page itself will appear to have loaded, per the url status bar, but the actual "page" will be blank white, possibly with a spinning symbol in the middle of the page.

Please note, this behavior occurs when I'm connected to a mobile network (T-Mobile US network anywhere from 2g to 4g - I travel a lot). When I'm connected to a fast wifi network, I generally don't have any issues. Since I'm actually using a mobile device, I would assume the mobile website would be optimized for mobile networks. Unfortunately, only the launchpad seems to be optimized. It's quite frustrating to see I have multiple unread emails and then be unable to load them.