Um.. I would go back and do the 'upgrade' then..
I think you're fairly stuffed - I assume you're using the 7.2 kernel, and associated libs.
And there'in lies your problem. DCOP is a messaging service which (if I'm correctly extrapolating my HPUX --> Linux) sends messages back and forth between your X-window desktop appilcations.
If you're getting DCOP errors I would imagine one of your libs is out of date. And even if you updated your libDCOP.so I'd have zero confidence that something else wasn't also broken.
My advice would be to 1) install RH8 on a new machine, copy across data / executables which reside on your machine.
2) Attempt the 'upgrade' you didn't do before to try syncing the libs required.
3) Backup your data to floppy / cd, re-install your machine with RH8 and enjoy the pretty icons..
Slick.