Checksums of ISO DVDs

Hi

I just transferred the powerpc iso images from your RHEL server to my desktop. Whilst I am able to open the supplement images on my MacOSX operating system, the ISO DVDs won't mount. When I open any ISO DVD in the mac Finder, I got this message: "Følgende diskbillede blev ikke aktiveret" (the iso image can't be opened). "RHEL4.8-ppc-AS-DVD ingen arkivsystemer, der kan aktiveres" (no file systems that can be activated). This applies to all DVDs from RHEL4 across to RHEL6. Just the CD Supplement ISOs can be mounted. Are the ISO images corrupted, or is it just that the MacOSX has some issues with opening them, i.e. checksums? I haven't got a clue which is the underlying file system that MacOSX cannot mount the RHEL DVD ISO images?

Thanking you in anticipation and I look forward to hearing from you.