Clearing APC opcode cache problem

Hi. I discovered issues with clearing the APC (opcode) cache. I used this code to clean the cache: apc_clear_cache('system'); apc_clear_cache('user'); But tests showed that the opcode cache is only sometimes cleared and strange behavior happens, that suddenly different versions of a file are executed. During my search for a solution I found this comment on stackoverflow: http://stackoverflow.com/a/3048694/1119601 Is it true that “apc_clear_cache('opcode')” has to be called to clean the opcode cache? If it is true, it would be great if this could be added to the documentation. Kind regards Christian