BlackBurd from our forums is one guy that takes matters into his own hands - with positive results. Complaining of how nethost or usb host never works on Windows Vista, he then made a revision for the PSP app.
The screenshots below are the comparisons between screens that use the regular usb host (left image) and the one using his revision (right image) - just click on the thumbnails to enlarge. If in case you can't spot the difference, the regular usb host says something like "bind: operation not permitted". On the other hand, his revision states, "bind: address already in use".
Download: PSP Host revision
Discuss: QJ.NET's PSP Development Forums