I login to my computer every day, in normal mode. No problem.
From time to time, I would have problems with my system, so I did an analysis using a program called "WhySoSlow", it gave me a relatively clean bill of health except for the following:
BIOS and chipset behavior
The highest measured SM BIOS interrupt or other stall was 599 microseconds. This is considered very poor. Your system will have difficulty handling multimedia in real-time and will be subject to unexpected stutters and unresponsive behavior.
I was trying to figure out how to update the BIOS and also to run other diagnostics--I forget which program I was using--but it insisted that I run any diagnostics or take any corrective actions in Safe Mode. That seemed reasonable, so I said yes when the program asked me if I wanted to login to Safe Mode. It then logged me out of regular mode and brought me into Safe Mode. In Safe Mode, however, I was unable to login. My password was rejected several times. I repeated the process several times and got the same result. I don't have the time--at this moment--to check to see which program I was trying to run, but I'll try to do that in a day or so.
I still have to figure out how to update my BIOS (there is an update available). And, of course, I still have to figure out how to login to Safe Mode.