SAP Note 27406 - FF707 tax entered incorrect, incorrect tax base

Symptom:

Error message FF707 'Tax entered is incorrect ...' where the displayed tax amount is the double, triple, ... amount of the correct tax.
The problem occurs when the document has more than one tax code or the 'Check' function is performed repeatedly on the tax screen.
If you post this document, the tax base might be twice or three times as large than the correct amount.

Cause and prerequisites

Modification in the User_exit 'USEREXIT_PRICING_RULE' (RV61AFZA) which also contains a line
STEU-KNPRS = 'B'. Modification was only provided for SD, but has effects on the tax calculation in FI.

Solution
1) Please enclose your modification with the following IF query (as indicated below): IF KOMK-KAPPL = 'V '.
* ..... modification
ENDIF.

2) Change in program LV61AU01

KOMK = COMM_HEAD_I.
KOMP = COMM_ITEM_I.
CLEAR STEU. <-------- insert

Additional key words

FB01, taxes, tax base, RFUMSV00