How do i fix the MonoPosixHelper reference

Im trying to unzip some stuff in an script, but the GZipStream is throwing an exception (im on a mac):

System.DllNotFoundException: MonoPosixHelper
  at (wrapper managed-to-native) System.IO.Compression.DeflateStream:create_z_stream (System.IO.Compression.CompressionMode,bool)
  at System.IO.Compression.DeflateStream..ctor (System.IO.Stream compressedStream, CompressionMode mode, Boolean leaveOpen, Boolean gzip) [0x00000] 
  at (wrapper remoting-invoke-with-check) System.IO.Compression.DeflateStream:.ctor (System.IO.Stream,System.IO.Compression.CompressionMode,bool,bool)
  at System.IO.Compression.GZipStream..ctor (System.IO.Stream compressedStream, CompressionMode mode, Boolean leaveOpen) [0x00000] 
  at System.IO.Compression.GZipStream..ctor (System.IO.Stream compressedStream, CompressionMode mode) [0x00000] 
  at (wrapper remoting-invoke-with-check) System.IO.Compression.GZipStream:.ctor (System.IO.Stream,System.IO.Compression.CompressionMode)
  at GZIPDecompressor.Decompress (System.Byte[] data) [0x00042] in /Users/peterbjornx/runescape client 3/runescape client/assets/runescape scripts/cache/GZIPDecompressor.cs:20

After LOTS of research and testing (and hair pulling, and begging), my opinion is to use DotNetZip. You need to copy some .dlls out of the mono framework to get it to work with built .exes.

Here is my Q that describes this: http://answers.unity3d.com/questions/10650/whats-the-best-way-to-implement-file-compression