$calc(8670007398507951000000000 / 4294967296) returns 2018643403078418, whereas Windows calculator reports "2018643403078417.9922193288803101". So far mIRC has been reliable for many things, but apparantly it's useless when dealing with large numbers. (I have an actual reason for making this division, I'm not just trying to see where mIRC will screw up.)