I have the same issue, and I believe it's related to the fact that the HP F300 series driver in HP Print Driver Update 1.1.1 is not a "modern" driver (PPD file, whatever that means). See
http://support.apple.com/kb/HT1893 and review the first note. It states that "Drivers that are not denoted as Modern Drivers cannot be selected when adding an IP printer or Windows shared printer." Then page down to the Deskjet F300 Series entry and note that the Modern Driver column is not checked. I suspect the printer connection over Airport looks like an IP Printer.
I also tried the F2100 and got my printing to work, although it doesn't seem to print colors, and I can't get an ink level readout.
Are these drivers supplied by HP, or does Apple develop them? Anyone know?