The lksctp-1.0.5-1.fc5.2 package in Fedora Core 5 does not match the kernel.
(The kernel appears to implement a more recent version of the API).
E.g., in kernel-2.6.16, the sctp_paddrparams struct has more fields than the
lksctp headers, which means that applications using that fail.
[I don't believe that the kernel sctp implementation has backwards compatibility
lksctp-tools-1.0.6-1.fc5 packages have been pushed for Fedora Core 5 which should resolve this issue. If these problems are still present in this version, then please make note of it in this bug report.
lksctp-tools-1.0.6-1.fc5 fixes the problem for me.
Package has been updated in FC6.