Check the top line on Wikipedia:
> [ˈændruː] r /j/
"It is frequently habitually written 'andoryuu' in Japan, but as a matter of fact the English has no 'y' sound after the R." So, "andoryuu" is the habit but "andoruu" is supposed to be more accurate. Does it sound right to you?
I notice as well that has had his name changed to on his Wiki page, so I'm thinking that "andoruu" is sometimes corrected to "andoryuu" by well meaning folks, but someone on Wikipedia is annoyed by this because it doesn't match up to their imaginary perfect representation of IPA in katakana.