Downloaded CS5 Master Collection onto new computer, but install says serial number is invalid. Had serial number checked by tech support rep and it is valid for CS5, says its a techincal issue. Help.

I purchased a new iMac yesterday.  Downloaded the CS5 Master Collection from the Adobe site, but install says my serial number is invalid.  I have double checked with my registered products on my profile and the number is correct.  Tech support with Adobe says this is a technical issue, but that my serial number IS valid for CS5.