Iso not same size ?

[Kokojo]

I swicthed my ISO for a new one, however, it is not the same size had it needs to be...

My personnal, pacthed, complete iso is 528,629 ko
And the new one i downloaded is 528,973 ko.

The pacth making program won't do anything since the two are not the same size ! What can i do, any ideas ?

[Kaijyuu]

Add some 00s at the end? Might make things go wonky, though.