Problem using COM in PHP

[Delphin]

I'm trying to use COM components in PHP script. I set the values in php.ini [com] section, added in dcomcnfg on server IUSR_MYHOSTNAME user to allow launch and access this COM(COM is on server), but when creating using new COM('My.Component') I receive

Unable to obtain IDispatch interface for CLSID {xx-xxxx...}: Server execution failed .

Maybe someone can help me ?

I'm using win2k+IIS6 + PHP4