in mongodb uploads_in_blob = False, because of https://code.google.com/p/web2py/issues/detail?id=1772, thanks Alan

VERSION

@@ -1 +1 @@
-Version 2.7.4-stable+timestamp.2013.11.17.09.27.55
+Version 2.7.4-stable+timestamp.2013.11.17.09.31.13

gluon/dal.py

@@ -5448,7 +5448,7 @@ class MongoDBAdapter(NoSQLAdapter):
     native_json = True
     drivers = ('pymongo',)
 
-    uploads_in_blob = True
+    uploads_in_blob = False
 
     types = {
                 'boolean': bool,