Dreamcard Won't Recognize Hypercard Stacks

[Iden Rosenthal]

I have just installed Dreamcard 2.7 and tried to open some Hypercard  
Stacks to convert them. They are unrecognized (grayed) in the file  
open dialog. Is there something I've missed? The stacks will run in  
Hypercard Player under Classic mode in OS X 10.4.5. They won't open  
in either Oracle Card or Spinnaker Plus (message says they are "not  
okay"). I realize these last two have nothing to do with Dreamcard  
but I thought I'd mention it just in case anyone else out there has  
any experience there as well.