Getting UART to work in 3.5

Hello. I'm trying to get uart to work in unity 3.5. There seems to be a problem importing Plugins. As it requires Unity3D 3.1, I'm pretty stuck. there is nothing that help document how it works, but basically, the problem is when loading plugins... here is the script :

 using UnityEngine;
 using System;
 using System.IO;
 using System.Runtime.InteropServices;
 
 public class Plugins : MonoBehaviour {
 
     public string[] PluginNames = {"VideoWrapper","TrackerWrapper"};
 
     // Use this for initialization
     void Awake () {
         AddToPATH("", true);
         for (int i=0; i<PluginNames.Length; i++) 
             AddToPATH(PluginNames[i], true);    
     }
         
     void AddToPATH(String subpath, bool useProjectDir)
     {    
 
         //.NET 1.1 has no string.Contains method or System.Environment class
         #if !UNITY_IPHONE
 
         string cwd = ApplicationDataPath();
         Debug.Log("[CWD]"+cwd);
         string dataDirName = "Plugins";
         String dataDirectory = Path.Combine(cwd,dataDirName);
             
         string separator;
         string environVar;
         if (Application.platform == RuntimePlatform.WindowsPlayer || Application.platform == RuntimePlatform.WindowsEditor)
         {
             environVar = "PATH";
             separator = ";";
         }
         else if (Application.platform == RuntimePlatform.OSXPlayer || Application.platform == RuntimePlatform.OSXEditor)
         {
             environVar = "DYLD_LIBRARY_PATH";
             separator = ":";
         }
         else
         {
             Debug.Log("Not using native platform app");
             return;
         }
                     
         string oldPath = System.Environment.GetEnvironmentVariable(environVar);
         Debug.Log("[Old Path]"+oldPath);
         String pluginPath;
         if (useProjectDir)
             pluginPath = Path.Combine(dataDirectory,subpath);
         else
             pluginPath = subpath;
 
         if(oldPath == null || !oldPath.Contains(pluginPath))
         {
             string newPath = oldPath + separator + pluginPath +"/";
             Debug.Log("[New Path]"+newPath);
             System.Environment.SetEnvironmentVariable(environVar,newPath);
             System.Environment.SetEnvironmentVariable("PATH",newPath);
         }else{
             Debug.Log("Path already contains plugin dir");
         }
                 
         #endif
     }
 
     public static string ApplicationDataPath()
     {    
         #if UNITY_IPHONE
         // Application.dataPath returns something like "/var/mobile/Applications/30B51836-D2DD-43AA-BCB4-9D4DADFED6A2/Data"
         // Unity 1.6 dataPath returns something like "/var/mobile/Applications/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX/myappname.app/Data"
         // Strip the "Data" part and add "Documents" instead
         string path = Application.dataPath.Substring(0,Application.dataPath.Length-5);
         if (path.Substring(path.Length-4) == ".app") //Unity 1.6
                 path = path.Substring(0, path.LastIndexOf('/'));
         return path + "/Documents";
         #else
         return Application.dataPath;
         #endif
     }
     
     public static string CreateFileFromAsset(string filename)
     {
         TextAsset textAsset = (TextAsset)UnityEngine.Resources.Load(filename);
         string filepath = ApplicationDataPath() + "/" + filename;
         BinaryWriter binWriter = new BinaryWriter(File.Open(filepath, FileMode.Create));
         binWriter.Write(textAsset.bytes);
         binWriter.Close();
         return filepath;
     }
     
 }

Thanks for viewing... Any other AR based plugins. for desktop PC are welcome... this however is the only one I can find...