Note that player updates are separate and indepdent from Xbox Dashboard updates.Persistant storage (or pstorage) is 192M of flash memory in the Xbox HD DVD drive that is used to store files for titles.
If Display works then it is a "soft hang": chapter skipping or pressing Menu may get you out of this state.
(I use the term "title" which you can read as "movie", its a habit I have got into from working on this for the last few years and is hard to break - forgive me).
If this happens when you try to start the disc then it means critical data could not be read.
For player bugs, be sure you are running the latest version of the firmware (see below).
Once you have confirmed you are running the latest player and the problem persists, then try searching the internet (or looking on the title-specific post that follows this one) for the error code and the title name which may lead you to a work-around.