The unzip package seems to have been built for the wrong architecture. Attempting to run the binary gives the error: "cannot execute binary file".
Running the file(1) command on /usr/bin/unzip reports:
ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.2.5, dynamicallt linked (uses shared libs), stripped
The unzip.control file from the .ipk says:
Package: unzip
Version; 55l-r0
Thanks,
Mark