Wrong encoding YEncoded file?

Question

I am using the NNTP library from this site, and I am trying to receive YEnc'd files.

When receiving some small dummy file using this library I get the following response:

Well all good, but when I decode the contents using YEnc32, I retrieve the info like:

F˜e˜a˜t˜u˜r˜e˜s B˜e˜nQ I˜X 1.41 R˜e˜v3 (SS) N˜o˜n-S˜t˜e˜a˜l˜t˜h 12˜X ----------------- (1.41 R˜e˜v5 (SS)) S˜t˜r˜i˜c˜t ˜d˜r˜i˜v˜e ˜s˜p˜e˜e˜d ˜c˜o˜m˜p˜l˜i˜a˜n˜c˜e - 12˜x ˜o˜n˜l˜y ˜f˜o˜r ˜g˜a˜m˜e ˜d˜i˜s˜c˜s (1.41 R˜e˜v5 (SS)) S˜u˜p˜p˜o˜r˜t ˜f˜o˜r SS ˜V2

When downloading using NewsLeecher I get the correct content without the ~.

I am using iso-8859-1 to decode the stream I receive from the usenet provider. What could be wrong?