(Also, someone could make this "an XXX bits float can store a YYY bits integer" a bit more clear as I personally still don't really understand it. I also remember vaguely some criticism of this system, that it is not very efficient? Matju? If you guys explain it here on the list I'll be happy to add it to the wiki.)
Andras
With a 32-bit float, some of the bits go to representing the exponent part, therefore there is not the full 32-bits available to represent an integer. http://en.wikipedia.org/wiki/Significand
It's worse than that though. Pd uses the %g format specifier when it writes out the pd patch (e.g. printf("%g", number)), so floats get simplified. It's possible to use a high precision number by entering it in the patch but when you reopen the patch it will have been simplified.
Martin