Perhaps it's possible that the seeds had been refrigerated but not stratified (not quite the same thing)? The stratification method Rich Howard uses is posted on his website:
http://www.ctdaylily.com/files...
A month does seem long for none of a cross to have germinated though. Without adequate stratification germination can be erratic but some usually germinate fairly quickly while the others in a batch can take weeks or months to get over seed dormancy.
