diff --git a/release/scripts/modules/bpy/utils.py b/release/scripts/modules/bpy/utils.py
index be52986bbad..06dbe8fd4cc 100644
--- a/release/scripts/modules/bpy/utils.py
+++ b/release/scripts/modules/bpy/utils.py
@@ -238,30 +238,29 @@ def relpath(path, start=None):
     return path
 
 
-_unclean_chars = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, \
-    17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, \
-    35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 58, 59, 60, 61, 62, 63, \
-    64, 91, 92, 93, 94, 96, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, \
-    133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, \
-    147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, \
-    161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, \
-    175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, \
-    189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, \
-    203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, \
-    217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, \
-    231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, \
-    245, 246, 247, 248, 249, 250, 251, 252, 253, 254]
-
-_unclean_chars = ''.join([chr(i) for i in _unclean_chars])
-
-
 def clean_name(name, replace="_"):
     """
     Returns a name with characters replaced that may cause problems under various circumstances, such as writing to a file.
     All characters besides A-Z/a-z, 0-9 are replaced with "_"
     or the replace argument if defined.
     """
-    for ch in _unclean_chars:
+
+    unclean_chars = \
+                 "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\
+                  \x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\
+                  \x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\
+                  \x2e\x2f\x3a\x3b\x3c\x3d\x3e\x3f\x40\x5b\x5c\x5d\x5e\x60\x7b\
+                  \x7c\x7d\x7e\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\
+                  \x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\
+                  \x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\
+                  \xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\
+                  \xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\
+                  \xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\
+                  \xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\
+                  \xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\
+                  \xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe"
+
+    for ch in unclean_chars:
         name = name.replace(ch, replace)
     return name
 
diff --git a/source/blender/imbuf/intern/thumbs.c b/source/blender/imbuf/intern/thumbs.c
index 234c8837b35..dcbd6df7ced 100644
--- a/source/blender/imbuf/intern/thumbs.c
+++ b/source/blender/imbuf/intern/thumbs.c
@@ -243,12 +243,12 @@ void IMB_thumb_makedirs()
 /* create thumbnail for file and returns new imbuf for thumbnail */
 ImBuf* IMB_thumb_create(const char* path, ThumbSize size, ThumbSource source, ImBuf *img)
 {
-	char uri[URI_MAX];
+	char uri[URI_MAX]= "";
 	char desc[URI_MAX+22];
 	char tpath[FILE_MAX];
 	char tdir[FILE_MAX];
 	char temp[FILE_MAX];
-	char mtime[40];
+	char mtime[40]= "0"; /* incase we can't stat the file */
 	char cwidth[40];
 	char cheight[40];
 	char thumb[40];