Hi Eric and Kathryn,
this has been caused by Koji (the Fedora Build System), which is set to export i386-pc-linux-gnu. I've overridden it in the configure, so it should be fixed now. An update is pending in the updates-testing repository for both F-7/F-8, or you can download the RPMs from Koji to test them:
http://koji.fedoraproject.org/koji/buildinfo?buildID=44887 (F-7)
http://koji.fedoraproject.org/koji/buildinfo?buildID=44886 (F-8)
Please if it works for you set a +1 in the updates system, as soon as it will reach karma +3 it will be pushed into the stable repository (or after pending 14 days):
https://admin.fedoraproject.org/updates/F8/pending/boinc-client-5.10.45-5.20080315svn.fc8
https://admin.fedoraproject.org/updates/F7/pending/boinc-client-5.10.45-5.20080315svn.fc7
In case of any troubles just mail me...or there is also bugzilla.redhat.com:)
Regards,
Milos