When seeing a V0 file, LameTag will say quality is = 97 (V0 and q3)
When seeing a 320kbps CBR file, LameTag will say quality is = 55 (V4 and q5)

Why is that, is this program crazy?

Pretty much. Whatever calculation is used is clearly obsolete, if it ever did make much sense. In this case it probably assumes that vbr is good and cbr is bad, without propely considering the effect of bitrate.

If the developers opened up this can of worms for updating, everybody would have a different opinion on how to quantify quality, so it is better to just let it go.

oh ok... I suspect that APP is mad.... ;-)

could also be it's a very old version or if it's lame somebody "tweaked" with the wrong settings.. muahaha

edit: by it i mean the 320 mp3 file, encoded with a very old encoder. mmk

Behold! The tag specification:

http://gabriel.mp3-tech.org/mp3infotag.html

I see that the quality value in the Lame tag is specifically "VBR Quality". This would explain why it has no real meaning in CBR mode.