Web Services > Update Assembly Item throws Please enter missing quantity level(s) error

Scenario:
Editing an assembly item using webservices returns USER_ERROR with the message Please enter missing quantity level(s)

Reason:
When Quantity Pricing Feature is enabled the SOAP Request needs to contain in the pricing matrix both quantity and value.
A corect format of the request is:

<s0:pricingMatrix replaceAll="false">	<s0:pricing>	<s0:currency internalId="1" />	<s0:priceLevel internalId="1" />		<s0:priceList>			<s0:price>				<s0:value>5.0</s0:value>				<s0:quantity>0.0</s0:quantity>			</s0:price>		</s0:priceList>	</s0:pricing></s0:pricingMatrix>