Corrections:
By Sequence above I mean Clip i.e. my problem is with the first clip in a sequence.
And lo and behold, suddenly the fade in icon appears but the fade in is done on the part of the clip that I have deleted!? Doesn't delete mean delete?
Later I open the project again, and now the fade in works as intended. This calls for more information on how DEL works in the beginning of the first clip of a sequence. Any info is most apperciated.