Hyphenation error on german word "einen"

[mikebarkmin]

"einen" should return "ei-nen". I have also tried to manually add it to the dictionary by inserting a line
"ei1nen"
after the pattern for
"ei1ne" Line 11739
But the pattern is not used.

Here is the test code:

import pyphen
dic = pyphen(filename="my.dic")
dic.inserted("einen")

P.S.: "eine" is correctly inserted and results in "ei-ne".