First off, take a look at these two examples please:
Example #1:
This problem has ailed me for a long time.
Example #2:
This problem has been ailing me for a long time.
Do you think you could confidently say that there really is a difference, however slight it might be though, in meaning between these two examples? Would you say that the first example gives the impression that the problem has troubled the speaker in the past for a long time, but does not trouble them anymore while in the second example the problem has been troubling the speaker for a long time in the past and most likely still continues to trouble them in the present?