I downloaded this for my rx3715 because the default that came with it didn't work. Now HP have discontinued it for some reason so its here if you want it.

Details:

mobileprinting4ppc03SE_en.exe

Note on HP:

Since 1992, HP has been committed to delivering a high-quality, complete printing experience for customers using mobile devices. Because customers can use similar mobile printing software offerings (see list, below) that are compatible with Pocket PC and Windows Mobile OS platforms, HP has decided to focus on other areas of its mobile printing and imaging strategy where solutions may not be so readily available. As a result, HP will discontinue HP Mobile Printing for Pocket PC and HP Mobile Printing SDK for Pocket PC, effective October 1, 2005. Any current customers / developers may receive basic phone support for six months thereafter, with all support for these products ending on April 1, 2006.

Yeah - doesn't make sense to me either.