I lost the money myself on 5dimes, but they have a very shady way of dealing with US customers. It's pretty common I'm sure, but the legality is strange. The credit cards get charged to random names when you fund, and they request you not tell fed ex that a package contains a check from an offsite gambling site.
I do like 5dimes and they are well respected and helpful, I just wish there wasn't so much behind the scenes tomfoolery and that the USA would just allow gambling and take a small percentage of winnings cashed out and let it be legal. Similar to gains when you cash out stocks. But that doesn't seem likely in the near future.