Net Monitor Skin Bug?

Hi!

I have a problem with the Net Monitor plugin:

Sometimes, the bar will show negative values like in the picture I attached.

Here is the source code of the skin:

Code:

[description]
SkinName = rh's Net Monitor Skin (Balken-Version)
Author = rh
URL = http://www.truelaunchbar.com
email = support@tsoftcentral.com

[general]
background = bg.png

[diagram1]
type = VertRow
picture = dia1.png
field = INLOAD
tile = 0
pos = 2 2
size = 4 19

[diagram2]
type = VertRow
picture = dia2.png
field = OUTLOAD
tile = 0
pos = 11 2
size = 4 19

Is this a bug or have I made a mistake while creating the skin?

I did NOT have that problem with earlier versions of the Net Monitor plugin up to 1.4

Regards,
rh