Well it's not really a bug...it's by design. The max size of a signed 64bit integer is from -9223372036854775808 to 9223372036854775807 (0x7FFFFFFFFFFFFFFF). Once you the exceed either the positive or negative limit, the integer overflows.
This can't really be fixed, unless darkone is up to writing some make-shift limitless large integer support (I've seen it done, I just forget what it's called :P). The disadvantage is, that it's much slower and we know how darkone feels about optimization and speed.
