Cacti is not graphing correctly

[skuli434]

Dears,
I have a problem with understanding something, on my graph for my Gig interface i have Current showing ( ex 4.44 ) Maximum ( 5.9 ) Average ( 4.3)
however on the graph it self it plots the line bellow 4. why is this happening, how should i debug this, i'm using Version 0.8.7b of cacti, i do have enabled 64bit counters,

please help
thank you

[BSOD2600]

1) cacti 0.8.7b?? you're way behind on security patches and updates. 0.8.8a is the latest.

2) post a graph debug output.