sorry but thats pretty much the case. i had one a while back and it did well for about 6 months and then started to die off. although i have heard of people haveing thiers for 2 years or more.good luck.
There seems to be some rumors that these species need a iron and manganese depleted environment rich in organics. This seems like a situation where I have to take back my advice to not put caulerpa into a system. Caulerpas take out alot of iron and manganese. A deep sand bed may also be in order. Heavily stocked tanks might also benefit these creatures. Baby brine shrimp may be a possible food source. This is all pure speculation but mimics the environments thqat they come from; slow moving turbid water in highly organic waters from lagoons behind the reef crests.
These animals should only be selected by experienced aquarists that are willing to put the time and effort they deserve into them. They live for at least tens of years in the wild there is no reason for them to die within a year except through neglect.