it may be just a symlink issue
go onto /usr/lib as root using pcmanfm or rox file managers
look for libjpeg.so
if its are there make a symlink named "libjpeg.so.8"
ln -s libjpeg.so.8 libjpeg.so
the libjpeg.so should be linking to a "libjpeg.so.8.0.8"
doing "slackpkg search libjpeg" inmy slackware setup gets
[ upgrade ] - aaa_elflibs-13.0-i486-2 --> aaa_elflibs-13.013-i486-4
[ installed ] - jre-6u19-i586-1
[ upgrade ] - libjpeg-v8-i486-1 --> libjpeg-v8a-i486-1
[uninstalled] - jdk-6u19-i586-1
so, it is a part of those pkgs
reinstall any of those pkgs if neccessary