barn63:
You need to expand on what you've given us, it's not very useful so far.
Necessary information would be:
1) The exact video card you are using (not just the chipset)
2) What have you downloaded from the ATi website?
3) What did you do on Slackware to install fglrx? What patches were you applying, etc?
4) Likewise for Slamd64 - what have you done so far, etc. Also, have you installed
cxxlibs5-3.3.4-x86_64-1 for Slamd64 beforehand?
5) What problem is Slamd64 reporting about trying to load the fglrx module?