Hello,

I believe this has been solved here already several times.
The problem is that VM does not store full information needed to recover the original price structure. Therefore, some parts must be calculated from the final price and that is where the rounding problem may appear. (at least for VM 1.x, but slighly similar problem is also with VM 2.x)

Therefore, you need to set rounding in VM and VM Invoice in the same way.
Please note this does not need ot be changed on DB level, but it may be set in VM configuration.

Additional comment:

The root cause was an issue in the floating point calculations in the PHP version we used.
So it's not ARTIO's fault.

However the poor support for a paid product is a reason to NOT RECOMMEND PURCHASING Artio's products.