Small issue using API to update parts

[Charley Tiggs <..hidden..>]

Hello folks,

I've got a puzzler of a problem that I've been trying to solve for the 
better part of two months.  It hasn't been that big of an issue before 
now because it was a relatively minor issue.  Now, though, it's 
elevating in importance.

Within the web application, a user wants to update a product. 
Approximately 3 months ago, I was assuming that the update did not need 
to include the vendor.  When the vendor was not included, the vendor 
that already existed with the part was removed.  To fix that, I learned 
to include the vendor.

Yesterday, about a 5 weeks later, I noticed that every time a product 
was updated, the vendor was duplicated.  Here's the CLI call to update 
the product:

cd /usr/local/ledgersmb;./ic.pl "taxaccounts=2150
&IC_inventory=1510--Inventory
&IC_income=4010--Sales
&IC_expense=5010--Purchases
&IC_tax_2150=0
&weightunit=lbs
&action=Save
&employee=script+user--10157
&login=scriptuser
&password=scriptuserpass
&path=bin/mozilla
&id=423431
&partnumber=18231240
&description=product+description
&pricegroup_1=Retail--10161
&pricebreak_1=
&customerprice_1=80.00
&customercurr_1=USD
&pricegroup_2=Wholesale--10163
&pricebreak_2=
&customerprice_2=30.00
&customercurr_2=USD
&customer_rows=3
&sellprice=40
&listprice=80
&lastcost=24.89
&unit=1
&weight=9
&markup=
&rop=0
&bin=
&obsolete=
&vendor_1=vendor+name--10433
&partnumber_1=18231240
&lastcost_1=24.89
&vendorcurr_1=USD
&leadtime_1=30
&vendor_rows=2"

My question:  Why would the vendor be duplicated?  I'm including the 
same information as is passed when going through the web interface for 
LedgerSMB.  What am I missing here?

For now, I've conditionalled the addition of the vendor.  If a vendor 
doesn't exist, then I'm not adding the lines to update the vendor.  But 
I'm still getting cases where the vendor is removed when the vendor is 
not added.

Any help/insight would be appreciated,
Charley