I am no expert on this stuff, but NSPR4K.DLL is part of the 'Netscape Public Runtime' and is installed by YUM. Check your system and make sure there is not another version of NSPR4K.DLL on your LIBPATH that would confuse YUM. Also make sure the one in your \usr\lib directory is correct (you can download the NSPR rpm from the Netlabs YUM page and manually extract).