I'd recommend re-installing ipkg from the terminal (in fact I'd recommend doibng everything from the terminal, but I'm strange like that).
Assuming you've clobbered ipkg, do the following:
1) download the (old - as otherwise the version will be wrong - not a major issue though) ipkg ipk file
2) put it in a temp dir and then run 'ar -x ipkg-blah.ipk', you'll get 3 files out.
3) then run 'cd / && tar -zxvf /path/to/temp/dir/data.tar.gz', this will extract the ipkg binary, then it should all work again (he says )
4) then run 'ipkg install /path/to/new/ipkg/file/ipkg-blah.ipk' (on the new version) OR if you have a network connection run 'ipkg install ipkg'
Si