Troubleshooting - Update Query optimization.

Problem Description:

Can you give me some insights on optimizing an update query to the PriceLevelPerItem table?

I am trying to update all of my existing price levels, and I'm looping through each inventory item in a specific category and updating the item in the PriceLevelPerItem table. Here is my SQL update

UPDATE PriceLevelPeritem SET PriceLevelPerItemCustomPrice = 38.35 WHERE ListID = '8000000D-1177165668' AND PriceLevelPerItemItemRefListID = '800004B9-1175625788'

I believe the ListID and the ItemRefListID are both jumps in points, but my driver status counts through the records and then stops at the record to update and appears to hang in access and VBDemo. I have gotten it to update at times, but others go into limbo, and with 22,000 items to update, I am hoping you can help me make this work. 

Solution:

The Intuit qbXML SDK requires us to modify the whole PriceLevelPerItem table with every insert or update, so the more levels and items you have will take longer. The problem is that Intuit requires the entire list to be updated with every operation, not a single row like the rest of QuickBooks!