[zivilyn]

I have a KPW3 (fm version 5.9.6 and jailbreak) and I found out that several of my Amazon-purchased books (4 in 500) didn’t show covers in grid view. I have searched on internet for some resolutions. I redownloaded the books and rebooted the device for several times, or connected to wifi and waited several days. All these didn’t work.

Then I launch the kindle explorer and looked into /mnt/us/system/thumbnails/. All cover thumbnails are saved in the directory. And I found out that those missing thumbnails had already been downloaded. But the difference between these 4 books and others is the scale. These books have a landscape cover scale (such as 303*200 or 303*180) while others have portrait cover scale (such as 303*404 or 303*500).

So I change the scale of the thumbnail file and renamed it as the original file (such as thumbnail_BXXXXXXXXX_EBOK_portrait.jpg). Then the books can show the covers correctly in grid view. But after I deleted and redownloaded the books, my revised thumbnail files were covered by original ones.

My question is how can I keep the revised thumbnail files after deleted and redownloaded the books.