I use Google Chrome and WGT games load just fine for me, pretty much several games a day.
You might want to review/modify/add to your computer and Chrome maintenance procedures.
I have my computer set up so my CCleaner application cleans up Chrome every time I close it. I also have CCleaner configured so it cleans my Flash Player Website Privacy Settings panel
I close Chrome before each game so it gets cleaned, and I only open one tab after I have restarted Chrome - the Game Client page.
This is what gets deleted from my Chrome browser - Browsing History, Download History, Cookies and other site and plug-in data, Cached images and files, Passwords, Autofill form data, and Hosted app data.
I also use CCleaner to keep my OS cleaned of temporary interment files, cookies, and other trash data.