I think investments counts as balance, if that is the problem.
Faucet can be claimed when your balance is zero. Maybe you have invested your balance in website. Which mean you don't have 0 satoshi in your account. Therefore, can't claim faucets.
Ok, so that is it... Thanks for your replies.
Would be nice to be able to claim on faucet even with an active investment, I let here my suggestion to YoloDice owner.

Wouldn't be logical or beneficial for the site ^^
You could claim faucet, gamble a bit and as soon as you've been a bit lucky invest the money.
You do that all the time and in a few weeks the site is ruined :p