Same problem- new Toshiba laptop would not sleep, even after factory reset.
Tried everything I could find online - no fix. Toshiba online support suggested a few things I'd already tried, then said take it to a local repairer.
They upgraded the bios - from 1.0 to 2.0, which solved the problem. Also - it was running hot, with the fan always going, CPA, RAM and HDD usage often approaching 100%, and short battery life.
After the bios upgrade battery life has tripled and it runs fast, quiet and cool.