Bit of a random issue, but has anyone run into issues setting the "billaddress" field via a user event script when the user event script is executed as a result of a web service "add" call? For some reason you cannot change the billaddress field in the user event script. However, if the user event script get triggered via a different context (UI, suitelet, scheduled script) it allows the use event script to change the billaddress.

im personally weary since this sounds like a lot of work, but you can try sharing the web service request that is creating the sales order and your user event code

Thanks battk, I tried that as well, but for whatever reason it doesn't let you modify any address information via user event script (this is on a Vendor Bill). Seems like a defect in NS that will never be fixed since it's so obscure :)