It means only one reason or more than it?
Got it. I was confused about the word "some". Would "for some reasons" be incorrect?
Yes. If you know the reasons you say 'I hate London for several reasons' before going on to specify them.
If you don't know why something doesn't work (as in emsr2d2's case) you say 'for some (unknown) reason' ('unknown' is optional).
I was warned against writing any 'thanks' without any new information but I like your contest so much. Thanks.
I mean your discussion.