[Solved] Calc mistakes in rounding numbers

[excelsior82]

I already posted that issue on oooforums.org today.
I was working with invoices when I saw a strange error with numbers that weren't rounded correctly.

I had a value of 5302,27 € (without VAT)
When I applied the 5.5% VAT (value*1.055), the result given by OOo is 5593.89

If I look up a third figure after the decimal point, the real value is 5593.895
The number should be rounded up to 5593.90

I've tested with OOo 2.2.0 under windows (french locale) and OOo 2.3.0 under ubuntu (french locale). The error happens on the both configurations.

I have noticed that if I ask OOo to show 2 figures or 3 after the decimal point, the two values aren't equal for OOo.
More spectacular, if I create a formula that simply point on the VAT-applied result, the value given is rounded rightly !

See this file for a practical example

I'd be very glad if someone can explain me these strange things

[Villeroy]

5302.27 * 1.055 = 5593.89485 (exactly)
Rounded to 3 digits: 5593.895 (the following 8 rounds up the 4)
Rounded to 2 digits: 5593.89 (the following 4 rounds down)

[excelsior82]

GOSH, that was so obvious !!! *kicks himself in the nuts*

Thanks you for the information, now I understand the company invoices is rounded to the third digit.

SOLVED.

OpenOffice is better than me