Missing contect menu on m4a, but codec installed

[c72831]

I have Windows XP 32 bit and installed dMC-r11.5 and the dBpoweramp-Codec-m4a.exe for converting m4a-files.
In the installation I checked "'Convert to' Menu Item" checkbox.

Converting from m4a to mp3 works, I GET the context menu on mp3 files in Windows Explorer, but if I right-click on a m4a file the context menu does NOT show "Convert to".

Is this a missing feature or can I solve this issue?

Thanks in advance!
Bernhard

[Spoon]

Re: Missing contect menu on m4a, but codec installed

Is the extension m4p? a iTunes store file?