Fixed, GLDEFS parser: we should check for duplicate entries within current resource, not globally.

Moved stuff around a bit in PK3Reader. Will it fix random crashes? I dunno, a least I was no longer able to trigger them...
Recompiled SharpCompress library using VS 2008, so it no longer references .net 4.0 stuff. Will it fix random crashes? See above.

Source/Core/Data/DataManager.cs

@@ -1710,6 +1710,7 @@ namespace CodeImp.DoomBuilder.Data
 			foreach (DataReader dr in containers) 
 			{
 				currentreader = dr;
+				parser.ClearIncludesList();
 				Dictionary<string, Stream> streams = dr.GetGldefsData(General.Map.Config.GameType);
 
 				foreach (KeyValuePair<string, Stream> group in streams)

Source/Core/Data/ImageData.cs

@@ -460,17 +460,16 @@ namespace CodeImp.DoomBuilder.Data
 					// Make a copy
 					return General.Map.Data.Previews.GetPreviewCopy(previewindex);
 				}
+				
 				// Loading failed?
-				else if(loadfailed)
+				if(loadfailed)
 				{
 					// Return error bitmap
 					return Properties.Resources.Failed;
 				}
-				else
-				{
-					// Return loading bitmap
-					return Properties.Resources.Hourglass;
-				}
+
+				// Return loading bitmap
+				return Properties.Resources.Hourglass;
 			}
 		}
 		

Source/Core/Data/PK3Reader.cs

@@ -78,9 +78,6 @@ namespace CodeImp.DoomBuilder.Data
 					sevenzipentries.Add(reader.Entry.Key.ToLowerInvariant(), s.ToArray());
 					fileentries.Add(new DirectoryFileEntry(reader.Entry.Key));
 				}
-
-				archive.Dispose();
-				archive = null;
 			} 
 			else 
 			{
@@ -91,6 +88,10 @@ namespace CodeImp.DoomBuilder.Data
 				}
 			}
 
+			// Get rid of archive
+			archive.Dispose();
+			archive = null;
+
 			// Make files list
 			files = new DirectoryFilesList(fileentries);
 			
@@ -128,7 +129,7 @@ namespace CodeImp.DoomBuilder.Data
 
 			if (enable && archive == null)
 			{
-				archive = ArchiveFactory.Open(location.location, (bathmode ? Options.KeepStreamsOpen : Options.None));
+				archive = ArchiveFactory.Open(location.location);
 			} 
 			else if(!enable && !bathmode && archive != null)
 			{

Source/Core/Data/PreviewManager.cs

@@ -20,7 +20,6 @@ using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Drawing.Imaging;
-using System.IO;
 using System.Drawing.Drawing2D;
 
 #endregion
@@ -145,7 +144,7 @@ namespace CodeImp.DoomBuilder.Data
 				Graphics g = Graphics.FromImage(preview);
 				g.PageUnit = GraphicsUnit.Pixel;
 				//g.CompositingQuality = CompositingQuality.HighQuality; //mxd
-				g.InterpolationMode = InterpolationMode.HighQualityBicubic;
+				g.InterpolationMode = InterpolationMode.NearestNeighbor;
 				//g.SmoothingMode = SmoothingMode.HighQuality; //mxd
 				g.PixelOffsetMode = PixelOffsetMode.None;
 				//g.Clear(Color.Transparent); //mxd
@@ -255,7 +254,7 @@ namespace CodeImp.DoomBuilder.Data
 
 
 		#if DEBUG
-		internal void DumpAtlases()
+		/*internal void DumpAtlases()
 		{
 			lock(images)
 			{
@@ -269,7 +268,7 @@ namespace CodeImp.DoomBuilder.Data
 					}
 				}
 			}
-		}
+		}*/
 		#endif
 		
 		#endregion

Source/Core/GZBuilder/GZDoom/GldefsParser.cs

@@ -6,8 +6,10 @@ using CodeImp.DoomBuilder.ZDoom;
 using CodeImp.DoomBuilder.GZBuilder.Data;
 
 
-namespace CodeImp.DoomBuilder.GZBuilder.GZDoom {
-	public sealed class GldefsParser : ZDTextParser {
+namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
+{
+	public sealed class GldefsParser : ZDTextParser
+	{
 
 		public delegate void IncludeDelegate(GldefsParser parser, string includefile);
 		public IncludeDelegate OnInclude;
@@ -511,5 +513,10 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom {
 
 			return objects.Count > 0;
 		}
+
+		internal void ClearIncludesList() 
+		{
+			parsedLumps.Clear();
+		}
 	}
 }