Different Tax % on the Service Invoice lines

sunnyk

Hi,
We are using Nav 5.0 Sp1 NA Version. The query is that i created a new service invoice with 3 lines. Since all the lines have same tax information like Tax area, tax group etc but still they have different Tax percentages. But when i press F9 the statistics shows the correct figure. Lets say based on the value of TAX parameters the value of the tax % should come is 7% my 3 lines shows like this,
1. 7.0023%
2. 6.9977%
3. 6.9992%