'Locking' Tags

I've just had to rescan my entire collection of music files.
I re-imported all my tracks into another program and it scanned them with its own system for the bpms - not very accurately I'm afraid! What makes it worse is the fact that it re-wrote all the existing bpms in the tags.
I've now re-scanned them all with Cross DJ, but would like to protect them against this ever happening again.
I know the easy answer is to stop using the other program, but I can't it's essential! I'd just like to force it to use the existing bpms in the mp3s, presuming that I can lock the tags first.
Would write protecting the actual mp3 files work, or would that cause problems with Cross DJ?

I re-imported all my tracks into another program and it scanned them with its own system for the bpms - not very accurately I'm afraid! What makes it worse is the fact that it re-wrote all the existing bpms in the tags.

I've now re-scanned them all with Cross DJ, but would like to protect them against this ever happening again.
I know the easy answer is to stop using the other program, but I can't it's essential! I'd just like to force it to use the existing bpms in the mp3s, presuming that I can lock the tags first.
Would write protecting the actual mp3 files work, or would that cause problems with Cross DJ?