can not play music files

I have just updated to version 2.48 and now i can not play music files.
when selecting a file to play an error box comes up.

The error says can not open file " files name" for playing! The operating system denied access to the specified file.

I am running windows 7 64 bit with full adminstration rights.

In th previous version it all worked ok

i have also tried to run mp3tag as an administrator - same problem

In another thread a user mentioned that a product called "Comodo Internet Security" has been denied access to the files.

Kind regards