More on mantis #7567. Two things:

- Increase the inventory cache timeout to 20 secs, so that the items will still be there when they are needed by the sim for rezzing
- Before rezzing attachs, make a call to GetMultipleItems so to fetch them all at the same time

OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs

@@ -304,6 +304,14 @@ namespace OpenSim.Region.CoreModules.Avatar.Attachments
                 m_log.DebugFormat("[ATTACHMENTS MODULE]: Rezzing any attachments for {0} from simulator-side", sp.Name);
 
             List<AvatarAttachment> attachments = sp.Appearance.GetAttachments();
+
+            // Let's get all items at once, so they get cached
+            UUID[] items = new UUID[attachments.Count];
+            int i = 0;
+            foreach (AvatarAttachment attach in attachments)
+                items[i++] = attach.ItemID;
+            m_scene.InventoryService.GetMultipleItems(sp.UUID, items);
+
             foreach (AvatarAttachment attach in attachments)
             {
                 uint attachmentPt = (uint)attach.AttachPoint;