The logs above were for two different books. Just to compare apples to apples, here's the log for the Windows 7 version for the book Neverwhere, same book as I used for the portable version above. I do know to delete the thumbnail from system/thumbnails on the kindle in between each send, to make sure it's making a new thumbnail:
Spoiler:
calibre Debug log
calibre 2.7 [64bit] isfrozen: True is64bit: True
Windows-7-6.1.7601-SP1 Windows ('64bit', 'WindowsPE')
('Windows', '7', '6.1.7601')
Python 2.7.8
Windows: ('7', '6.1.7601', 'SP1', 'Multiprocessor Free')
Successfully initialized third party plugins: Kindle and Mobipocket DeDRM && Inept Epub DeDRM && Quality
Check && Kindle 2, 3, 4, Touch, PaperWhite Device Interface Paperwhite thumbnail FIX MOD
Starting up...
Started up in 3.94 seconds with 333 books
Job: 1 Get device information started
DeviceJob: 1 Get device information done, calling callback
DeviceJob: Job:1 1 Get device information callback returnedGet device information
finished
Job: No details available.2
Set library information started
DeviceJob: 2 Set library information done, calling callback
DeviceJob: 2 Set library information callback returned
Job: 3 Get list of books on device started
DEBUG: 0.0 USBMS: Fetching list of books from device. Device= KINDLE2 oncard= None
DEBUG: 0.0 USBMS: dirs are: E:\ documents
DEBUG: 0.1 USBMS: scan from root False E:\documents
DEBUG: 0.3 USBMS: count found in cache: 18, count of files in metadata: 18, need_sync: False
DEBUG: 0.3 USBMS: Finished fetching list of books from device. oncard= None
DEBUG: 0.3 USBMS: Fetching list of books from device. Device= KINDLE2 oncard= carda
DEBUG: 0.3 USBMS: Fetching list of books from device. Device= KINDLE2 oncard= cardb
DeviceJob: 3 Get list of books on device done, calling callback
DeviceJob: metadata_downloaded: Starting set_books_in_library
DeviceJob: set_books_in_library: books to process= 18
DeviceJob: set_books_in_library finished: time= 0.0150001049042
DeviceJob: metadata_downloaded: updating views
DeviceJob: metadata_downloaded: syncing
DeviceJob: metadata_downloaded: refreshing ondevice
DeviceJob: metadata_downloaded: sending metadata_available signal
DeviceJob: 3 Get list of books on device callback returned
Job: 1 Get device information finished
No details available.
Job: 3 Get list of books on device finished
No details available.
Job: 2 Set library information finished
No details available.
Job: 4 Upload 1 books to device:Neverwhere started
Device using plugboard azw3 KINDLE2 None
Setting metadata in: Neverwhere at: C:\Users\Cath\AppData\Local\Temp\calibre_wqpqme\kh t_edcaltmpfmt.azw3
DEBUG: 6.6 USBMS: uploading 1 books
APNX META: guid: 3d0cd20a
APNX META: ASIN: 6c29e792-40fc-4ce2-a248-f0d0d0dd61db
APNX META: CDE: EBOK
APNX META: format: MOBI_8
APNX META: Name: Neverwhere
APNX Content Header: {"contentGuid":"3d0cd20a","asin":"6c29e792-40fc-4ce2-a248-
f0d0d0dd61db","cdeType":"EBOK","format":"MOBI_8"," fileRevisionId":"1","acr":"Neverwhere"}
DEBUG: 7.7 USBMS: finished uploading 1 books
DeviceJob: 4 Upload 1 books to device:Neverwhere done, calling callback
DEBUG: 7.7 USBMS: adding metadata for 1 books
DEBUG: 7.7 USBMS: finished adding metadata
DeviceJob: set_books_in_library: books to process= 19
DeviceJob: set_books_in_library finished: time= 0.00100016593933
DeviceJob: 4 Upload 1 books to device:Neverwhere callback returned
Job: 5 Send metadata to device started
DEBUG: 7.8 USBMS: starting sync_booklists
DEBUG: 8.1 USBMS: finished sync_booklists
DeviceJob: 5 Send metadata to device done, calling callback
DeviceJob: 5 Send metadata to device callback returned
Job: 4 Upload 1 books to device:Neverwhere finished
No details available.
Job: 5 Send metadata to device finished
No details available.