I've recently noticed a similiar problem. Sometimes the cursor does not reveal the cache name that can be clicked on to bring up the box link. For me, zooming in and out a bit re-initializes proper function, so it's just irritating. The problem doesn't happen with all cache icons. The glitch appears random, so I can't say I'm doing something specific to cause the error. To aid in troubleshooting, I'm using Windows 7, IE9, with current versions of Flash and Java. Hope this helps in finding an answer.
Thanks for that. I've found the same random issues with some but not all icons. Will try a different browser, maybe Firefox and see what happens. Thanks again