Firstly, can you check the actual firmware version number and post that. Far to often people state they have the latest firmware installed and they don't.
I don't know what is happening, so I need more information:
- What format are these books? epub, CBZ, CBR or something else?
- How big is large? Both in file size and number of pages.
- How many books are you deleting? My first guess is 10, but, the "volumes" might not refer to a single book.
- What happens if you delete only one book?
- What happens if you delete the book through the Kobo interface?
- Is there much space available on the device?
- What is displayed during the boot loop?
- What is displayed after disconnecting from the PC and before the reboots start?