Strange round behaviour w/ more than 2 decimals

Hi. I'm having some strange round behaviour when using 4 decimals.

If I use ROUND(1.8947, 2), it should return 1.90, but it does return 1.89.
Rounding to 3 decimal places, then 2 (eg.: ROUND(ROUND(1.8947, 3), 2) ) then
I get 1.90!
This way, when rounding, ROUND is considering only decimal places parameter
+ 1 to determine which is the rounding (ROUND(1.8951, 2) returns 1.90).

I've tested in 8.1.3 and 8.2.4.

Is it expected to work this way? There's a way to "force" the round to
consider all the decimal places?

Thanks,
Fernando Pinheiro