Assuming that the file posted here have been renamed (because the actual files in use should be named FSX.CFG and DLL.XML) and are exact copies of the actual file in use, your DLL.XML looks fine.
Your FSX.CFG still has a bglmanx.dll entry with 0, try changing it to 1 OR, just remove the whole [trusted] section: it will be recreated when you start FSX again, asking again for permission to run every module and every gague, which of course you need to reply Yes to all of them.
Also, there are more suggestions here at the PMDG website:
http://ops.precisionmanuals.com/wiki/PMDG_747-400X_FAQ#Error_Number:_0x800C0005_during_installLook the section about registering all those dll.
As you can see, antivirus problems and failing to asking to trust the module, is not a problem specific to our products...