diff --git a/OpenRa.DataStructures/float2.cs b/OpenRa.DataStructures/float2.cs
index dd80f7fc70..6b57223279 100644
--- a/OpenRa.DataStructures/float2.cs
+++ b/OpenRa.DataStructures/float2.cs
@@ -26,7 +26,7 @@ namespace OpenRa
 
 		public static float2 operator -(float2 a) { return new float2(-a.X, -a.Y); }
 
-		static float Lerp(float a, float b, float t) { return (1 - t) * a + t * b; }
+		static float Lerp(float a, float b, float t) { return a + t * (b - a); }
 
 		public static float2 Lerp(float2 a, float2 b, float t)
 		{
diff --git a/OpenRa.FileFormats/IniFile.cs b/OpenRa.FileFormats/IniFile.cs
index cb3a158120..e4d931a1e3 100644
--- a/OpenRa.FileFormats/IniFile.cs
+++ b/OpenRa.FileFormats/IniFile.cs
@@ -17,8 +17,15 @@ namespace OpenRa.FileFormats
 			while( !reader.EndOfStream )
 			{
 				string line = reader.ReadLine();
-				if( !ProcessEntry( line ) )
-					ProcessSection( line );
+
+				if (line.Length == 0) continue;
+
+				switch (line[0])
+				{
+					case ';': break;
+					case '[': ProcessSection(line); break;
+					default: ProcessEntry(line); break;
+				}
 			}
 		}
 
@@ -27,9 +34,6 @@ namespace OpenRa.FileFormats
 
 		bool ProcessSection( string line )
 		{
-			if (string.IsNullOrEmpty(line) || line.StartsWith(";"))
-				return false;
-
 			Match m = sectionPattern.Match( line );
 			if( m == null || !m.Success )
 				return false;
@@ -43,9 +47,6 @@ namespace OpenRa.FileFormats
 
 		bool ProcessEntry( string line )
 		{
-			if (string.IsNullOrEmpty(line) || line.StartsWith(";"))
-				return false;
-
 			Match m = entryPattern.Match( line );
 			if( m == null || !m.Success )
 				return false;
diff --git a/OpenRa.Game/Sprite.cs b/OpenRa.Game/Sprite.cs
index 5aa690b4aa..857d7d4d09 100644
--- a/OpenRa.Game/Sprite.cs
+++ b/OpenRa.Game/Sprite.cs
@@ -11,6 +11,7 @@ namespace OpenRa.Game
 		public readonly Sheet sheet;
 		public readonly TextureChannel channel;
 		public readonly RectangleF uv;
+		public readonly float2 size;
 
 		internal Sprite(Sheet sheet, Rectangle bounds, TextureChannel channel)
 		{
@@ -23,6 +24,8 @@ namespace OpenRa.Game
 					(float)(bounds.Top + 0.5f) / sheet.Size.Height,
 					(float)(bounds.Width) / sheet.Size.Width,
 					(float)(bounds.Height) / sheet.Size.Height);
+
+			this.size = new float2(bounds.Size);
 		}
 
 		public float2 MapTextureCoords(float2 p)
@@ -31,6 +34,8 @@ namespace OpenRa.Game
 				p.X > 0 ? uv.Right : uv.Left,
 				p.Y > 0 ? uv.Bottom : uv.Top);
 		}
+
+		public float2 Size { get { return size; } }
 	}
 
 	public enum TextureChannel
diff --git a/OpenRa.Game/Util.cs b/OpenRa.Game/Util.cs
index 72b60520cb..c94d240df1 100644
--- a/OpenRa.Game/Util.cs
+++ b/OpenRa.Game/Util.cs
@@ -31,7 +31,7 @@ namespace OpenRa.Game
 		public static Vertex MakeVertex(float2 o, float2 uv, Sprite r, int palette)
 		{
 			return new Vertex(
-				float2.Lerp( o, o + new float2(r.bounds.Size), uv ),
+				float2.Lerp( o, o + r.Size, uv ),
 				r.MapTextureCoords(uv), 
 				EncodeVertexAttributes(r.channel, palette));
 		}
diff --git a/OpenRa.TechTree/TechTree.cs b/OpenRa.TechTree/TechTree.cs
index ee9a757472..fae4a26ae3 100644
--- a/OpenRa.TechTree/TechTree.cs
+++ b/OpenRa.TechTree/TechTree.cs
@@ -9,6 +9,9 @@ namespace OpenRa.TechTree
 {
 	public class TechTree
 	{
+		static IniFile rules;
+		static IniFile Rules { get { return rules ?? (rules = new IniFile(FileSystem.Open("rules.ini"))); } }
+
 		Dictionary<string, Item> objects = new Dictionary<string, Item>();
 		public ICollection<string> built = new List<string>();
 
@@ -54,13 +57,12 @@ namespace OpenRa.TechTree
 
 		void LoadRules()
 		{
-			IniFile rulesFile = new IniFile(FileSystem.Open("rules.ini"));
 			IEnumerable<Tuple<string, string, bool>> definitions = Concat(
 				Lines("buildings.txt", true),
 				Lines("units.txt", false));
 
 			foreach (Tuple<string, string, bool> p in definitions)
-				objects.Add(p.a, new Item(p.a, p.b, rulesFile.GetSection(p.a), p.c));
+				objects.Add(p.a, new Item(p.a, p.b, Rules.GetSection(p.a), p.c));
 		}
 
 		public bool Build(string key, bool force)