get "notimplementedexception" or "NotSupportedException"

Feb 12, 2013 at 3:34 PM

I sometimes get an exception when saving a zip file, using ZipFile.Save().
When working with it's "The method or operation is not implemented".
When working with it's "Specified method is not supported".

It's not always happening. I couldn't point out the exact scenario, but I saw that the first access to the save() function works ok, but repeated calls will most likely fail as described above.

Any idea what happens here?