'MROUND' different between Excel and gnumeric?

'=mround( 0.499999999999999, 0.2 )' ->  0.4000000000000000  in Excel 2010 64-bit, Win7, 64-bit,  
                                    ->  0.6000000000000001  in gnumeric, win 1.12.17, lin 1.12.51, 

(i know! Excel is weird, have seen: the code is weird, have seen: the programmer was aware of ...)
on a first glance the Excel result is 'nearer' ...