Not really a "Thrive" thing. It's happened on Nook Colors. I'm not sure what other tablets. No, Toshiba has not fixed it.
Hold the power button down until it shuts off. Pull out the battery for a few minutes and put it back in and restart.
Samsung Tab 3 (7 in) • Deletrious ROM V1.6 /TOSHIBA Thrive • Pio's Team Baked BlackBean ROM 4.1.2/Samsung Galaxy Note2 • Temasek v37 kitkat (4.4.2)/HTC EVO 4G • Decks Reloaded ROM/EVO Shift• JellyBelly ROM/Samsung Galaxy Note I (i717)•CM11 (4.4.2 kitkat) /Samsung Galaxy S3 •DanKang 4.3.1 ROM