Ubercart

So here's my problem.

I've set up a shop and a bunch of products that needs different taxes.
On my first product line (everything & shipping) only one tax is applied (TPS 5%)
On the second one (only on teaching material & shipping) I first need to add the TPS and a second tax TVQ (8.5%)

This is how it should looks like :

Order subtotal $65.90
Shipping $10.00
Subtotal $75.90
TPS 5% $3.80 -------------> applied to the subtotal including shipping
TVQ 8.5% $0.89 ------------> In this case the TVQ is only applied on the shipping since there is only books in the current order but needs to separately add the TPS on the shipping and then add to it the TVQ (so on $10.00, 5% represent $0.50 we then multiply $10.50 by 8.5% to get the TPS)
Total $80.59

But this is what i'm getting :
see first attachment

When I should get this :
see second attachment

(Sorry the screenshots are in french but you get it)

My taxes are set up like this :

TPS : 5%, Apply tax to any product regardless of its shippability., applied to all product types, taxed line items : Shipping
TVQ : 8.5% Apply tax to any product regardless of its shippability., applied to all product types, taxed line items : Shipping & tax

I believe the system is taxing wrongly because of the taxed line items : tax but can't quite figure out what is going on.

Is it possible to get some help here?
I'm using version UC 3