It's nothing to do with the samurai portion of the title. It's from that being a derivative of an IBM PC driver.
I have no idea about only being able to type s-a-m before it crashes unless you have your game list & select column set to where it's hitting 1 that crashes it as you type it in. Can you type other titles out fully?
If I remember correctly, at 1st there were quite a few like this,(like around v185) including Neo-Geo I believe, but they've all slowly returned to working as usual either by being fixed on purpose or just inadvertent changes to the code that solved it. That is just my best guess mind you...
For now, if you wish to remove the ones that crash MAME from your lists, here are the 1s I know of. If anyone finds any more, add them to the list.
For certain, any of the drivers from these source files will crash it:
Any of the other IBM drivers work fine:
Also, the above drivers do not cause crashes in anything other than MAMEUI64 as far as I know. So if you need to use 1 of those just run it from the command line or internal UI or another UI of your choice...
Pessimist: Oh, this can't get any worse!
Optimist: Yes, it can!