Here is a third beta test for Teensyduino 1.40.

Old beta download links removed. Please use the latest version:

Changes since Teensyduino 1.40-beta2

USBHost_t3 keyboard improvements (Kurt, Frank)
Update Snooze (Duff)
Fix USBHost_t3 hub bugs (thanks Kurt)
Fix missing upload error messages in newer Arduino
Show warning for certain counterfeit boards, still allow upload
Fix race condition causing "Teensy Loader is unable to read your compiled sketch (r)"