Foxy Fingernailed Again

Candidate for anger management?

Foxy Brown's fingernails have once again landed the singer in hot water -- this time, she was booted off a Royal Caribbean cruise because she flipped out after missing her at-sea manicure appointment ... TMZ has learned.

Brown has a storied history when it comes to cosmetics -- in 2004, she faced assault charges for allegedly beating up two nail salon employees ... and again in 2007 after allegedly beating up a beauty store employee.

All she wanted was special treatment....