ITunes 10.5.3 crashes when an ePub file is loaded onto an iPad

Question

I just updated iTunes to 10.5.3 (on two Macs).  Both are running the latest Snow Leopard.
Now, on either system, when I attach an iDevice (iPad-1st Gen.) and drop an ePub file onto it, via the newly-updated iTunes, iTunes crashes.
This is happening with ePubs that I produce (this is how I test) -- yes, these are files that have passed validation.  This also happens with books (ePub files) that were previously 'dropped' into the iPad just fine -- i.e., books purchased from independent book sellers.  Now these ePub files are causing the same crash when I drop them onto the attached iPad.  (The books already loaded onto the bookshelf do still seem to be rendering just fine.)
I have done a restart of each system -- same effect.
This has nothing to do (directly) with the new iBooks app or the new authoring tool (which I've not downloaded) - other than apparently a new iTunes (and maybe a new iOS rev.?) was issued to support the new books stuff.
This really impacts my ability to test book production so any ideas are most welcome.  Thanks!

Answer 1

I spent time today at the Apple Store - the Genius ran diagnostics on my crash report.  Here's what he concluded:
1) The connected iOS device is not set up as syncing to the Mac I connect it to.  (Technically, that is correct in that I "sync" nothing through iTunes Sync, meaning I have none of those checkboxes checked. I do all file syncing manually -- that's ePubs, PDFs, music, videos, etc.  So far only the dragged ePub files are crashing iTunes.  I sync my calendar and contacts through Mobile Me.)  The crash report indicated that iTunes is expecting to be Syncing this "official" way:  files into the local Library (by purchase; by dragging) and then iTunes-managed movement to/from an iOS device.  That some of us have used drag-and-drop directly onto the attached iOS device before this update and that worked is coincidence -- i.e., not the supported technique; no promises.
2) Oliver's "workaround" is close to the officially supported way - i.e., get the ePub file into the iTunes Library on the computer and then onto the iOS device.
3) Other alternatives that don't go via iTunes are: sending as email attachment to the iOS device (as I described above); use a 'cloud' server such as DropBox.  These approaches don't bulk up your local Library with your ePub files.
4) Watch for iTunes 10.5.4 and when you see it, update to it.  (Even tho' this isn't technically an admitted 'bug' crashing is never good and it may be corrected if enough crash reports are sent to Apple.)