Problem while MRKO

Dear All,

I have a pipeline material and i maintain inforecord with tax code (I0 - Nil Tax) and source list for that material.

While MB1A, issue(201 P) from pipe line .....my FI entries are as

(GBB-VBR) Consumption Acct - Dr

(KON) Pipeline Liabillity Acct - Cr

But While Doing MRKO to settle Pipeline

system Gives me this error in

No taxes on sales/purch.are allowed for account 2030190 1000, I0 is not allowed

here 2030190 Pipeline Liabillity Acct

1000 Company Code

I0 Tax Code

Please help !

Regards,

Pardeep Malik