How to re-create:
make a Sync-Shell and switch to it (the bug only happens in a shell)
Create a Seared Bricks block and you get the book Mighty Smelting, do it again and you get another and so on
it stops working if you re-log while in the shell.
it doesn't stop other shells from having the bug happen tho the re-logged shell seems to have stopped having the issue permanently

Versions used to re-create this bug:
TinkersConstruct 1.5.5.4
Sync 2.2.1
MC 1.6.4

-Toby