withholding tax & payment problem

Hi,

I have defined two WHT Types & Codes as follows and assigned the both to a vendor:

WHT Type WHT Code Description

PP PP WHT during Payment Posting (downpayment)

IP IP WHT during Invoice Posting

At the time of making the Downpayment, the system correctly picks only the first WHT type & code i.e. PP

But at the time of Invoice Posting, it pops up both IP & PP, and I have to manually remove the PP. I want to avoid this.

How can we make the system pick only IP at the time of Invoice Posting (just the way it picks only PP during downpayment)?

Since i'm going to use this in a Rent recurring entry (which will be processed via Batch processing in Background), its important that users don't have to manually remove the inapplicabe WHT code.

Please help!

Thanks,

Amit Bharti