Tonight I burned the 4.0 firmware ISO to a CD-R and updated my backup A30 since it was quite old at Ver 1.1. So far so good, seems to work smoothly. My #1 A30 which has ver 1.3 is in its box for a while while I test 4.0 on problem discs, etc. Suppose if 4.0 works as well as 1.3 I'll upgrade that player too since Toshiba surely must have fixed lots of things in 1.3, 2.0 and 3.0.
Took ten minutes for the upgrade and I have to admit I was getting worried since it cycled from VERUP to STEP 1/4, STEP 2/4, STEP 3/4 in less than five minutes then seemed hung on STEP 4/4. Was thinking something went very wrong but at the ten minute mark the tray ejected and the player shut off. Grabbed the CD-R, then a power on and it sure seemed the Welcome screen stayed on forever. But yay, it came up and wasn't bricked! Like the on screen message says, don't power off! Let it shut down itself.