Error message while saving record

Hi guys,

Does anyone know what this error message mean, we are trying to save records to My.Package.List
class and sometimes we get this error message at first but when I try to save the same record again from the Terminal it does save fine? 

"Error:0 4"_$c(1,4,4)_"«"_$c(22,30,1)_"My.Package.List"_$c(2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1)_"

Thanks