mysqladministrator and differents query cache hits graphs

[MAS!]

I wonder why with tre different MySQL administrator istances I have 3  
different QueryCache Hitrate on the same database, in the same time :(

I'm trying with:

- MySQL administrator v.1.2.12 (Ubuntu 8.10): the query hitcache is  
always at 100% (average 100)

- MySQL administrator v.1.2.5rc (Debian etc): average 86%

- MySQL administrator v.1.2.12 (Max OS X 10.4.11): average 40%

NB: the graph formula is always the same (the default one), then:

(^[Qcache_hits]/(^[Qcache_hits]+^[QCache_inserts]+^ 
[Qcache_not_cached]))*100

which one is correct?
and why I have so different results?!
thank you in advance
bye
MAS!