[boost] iterator adaptors problem

Hi, I have a problem with iterator_facade usage. Error is reported by Comeau and MIPSPro compilers: An error output can be found in regression tables: http://tinyurl.com/37mxz The compiler is reporting, that iterator_core_access cannot access the private equal() function, althought it has been marked as friend. My iterator class is publicaly derived from iterator_facade and privately from another templated class. Is it possible, that multiple inheritance creates the problem? Thanks for any help. Pavol