They are correct. Postnet barcodes should have either 32 bars for 5-digit zip code, 52 bars for 9-digit zip code, or 62 bars for 9-digit zip code and delivery point. See this reference.
Intelligent Mail Barcodes have 65 bars.
I don't know anything that has 67. What type of data are you supplying for the postnet barcode rule?
Also, what version of FusionPro, which platform (Mac or Windows), and which version of operating system?