Nektar has posted an updated Windows driver for the P4/P6 (from version 1.2.3.1 to 1.2.3.5). A firmware update is also included. Once you've run the installer, you'll need to run the Firmware Updater (nkupdate.exe; a shortcut to it is created during the install). Here's a link to Nektar's firmware update instructions.
 
http://www.nektartech.com.../it.I/id.830/KB.666/.f
 
Edit: I have yet to find any release notes for this update. Anyone have any idea? So far, no problems with the update.