I have read the problems with 16:04 etc not shutting down correctly. I think this problem is slightly different. I had ubuntu 15 for a longtime then upgraded to 17 All was well with 17 but unfortunately I had a hard disk failure. I have now replaced the hard drive and re-installed 17:04
The problem now is that on shut down the laptop (Toshiba L50) hangs at the last part of shutting and I have to press and hold the power button. I have also noticed it doesn't suspend on shutting the lid. It all worked before on this laptop with its original drive.
I checked the bios settings and they haven't changed. I first noticed it after the install process had completed and i removed the CD and pressed enter. Any help is appreciated. swlr