Wrong tax amount in MIRO

Dear All

Scenario is explained as below :-

Whenever there will be service tax on software in my PO VAT No Deductable will be calculated on Net Price + Service tax on Software in other case VAT wil be calculated on Net Price only.

ZSER - Condition type for Service tax on Software

ZVRO - VAT Non Deducatble (Copied from JVRO).

I have made changes in tax procedure TAXINN such that ZVRO in calculated on Net Price and Service tax on S/w i.e. ZSER.

I made a PO with net price 290 INR and used condition type ZSER@10.3% and ZVRO@5%. In PO ZSER is 29.87 INR and ZVRO is 15.99 INR whic is correct but at the time of MIRO, when I tick on calculate tax,tax is appearing as 14.50 INR.

I think VAT is getting calculated on 290 INR i.e. 5% of 290 INR = 14.50 INR.

Please suggest how to get correct tax amount in MIRO.

Regards

SK