BUG #8317: ROUND(double*1/2) != ROUND(1/2*double)

The following bug has been logged on the website:

Bug reference:      8317
Logged by:          Rémi
Email address:      remi.cura@gmail.com
PostgreSQL version: 9.2.4
Operating system:   Ubuntu 12.0.4 32 bits hosted by a VirtualBox
Description:

Hello;
I ran into a strange behaviour.
Initially it showed in a group by, but is also happens in regular select :


example :
SELECT 2*ROUND(1/2*3.2)
--> gives 0
SELECT 2*ROUND(3.2*1/2)
--> gives 3


Obviously both should return the same thing, preferably 3.
It looks like a bug to me, or at least a non desirable behaviour.


Cheers,
Rémi