Thank you, Kinoc for adding: When accessing slower web sites or proxy services

300 msecs can be too slow and cause a timeout to occur. This is reported when 
llHTTPRequest times out but may not be reported for other functions like 
osSetDynamicTextureURL. This sets the time out to 30 seconds. It appears 
that the value affects not just llHTTPRequest's.

OpenSim/Region/Environment/Modules/ScriptsHttpRequests.cs

@@ -88,7 +88,7 @@ namespace OpenSim.Region.Environment.Modules
         private Queue<HttpRequestClass> rpcQueue = new Queue<HttpRequestClass>();
         private object HttpListLock = new object();
         private string m_name = "HttpScriptRequests";
-        private int httpTimeout = 300;
+        private int httpTimeout = 30000;
 
         // <request id, HttpRequestClass>
         private Dictionary<LLUUID, HttpRequestClass> m_pendingRequests;