correct price if shipment by price, incorrect if by weight..

[giuly]

ZC 1.5.5e, now I have strange issue, the module zone (I inserted 9 zones), works perfectly if I select mode by price, works wrong if I select by weight!!!

These settings for zone IT, first zone
3:5.8,5:7.0,15:10.0,25:12.0,30:16.0,50:20.0,100:30.0

so under 3 of weight/price it has to be 5.8+vat (22%), instead price of item is 19.90 so it calculates
-by price 12.0+22%VAT

-by weight 10.0 + 22%VAT instead of 5.8+VAT (item weight is 3, so or 5.8 or 7.0 but not 10.0)

system sees that weight 6 (but I insert in admin product page 3)

[giuly]

Solved in this way modifying
admin
configuration>shipping/packaging
Package Tare Small to Medium - added percentage:weight
set to 0:0

SOLVED!

[mc12345678]

Solved in this way modifying
admin
configuration>shipping/packaging
Package Tare Small to Medium - added percentage:weight
set to 0:0

SOLVED!

What was in that field before setting 0:0?