I'm getting a number of strange problems with modules and settings as well.  I can go into the settings of a module and make a few config changes, click update and the changes don't take effect for the module.  I sometimes get logged-off from an admin account automatically after only being logged in for 5 to 10 minutes - sessions on the server are set to 60 minutes.  Adding modules to a page as an admin can be a problem - sometimes it shows and sometimes it disappears when I refresh my browser.

I've gone in to the host performance settings of DNN 4.9.2 and set everything to 'no caching' and 'No Compression' with peristence as 'Page' and caching as 'Disk'.  Turning off the cache helped some problems with modules disappearing and site & module settings not being committed properly after an update.  I still get some strange outcomes sometimes - the auto logout problem is interesting.

I have 1 DNN portal running 4 sites on a dedicated Win Server 2003 SP2 (with up-to-date patches) box - IIS 6, SQL Server 2005 Enterprise SP2, .NET 1.0, .NET 2.0 and .NET 3.5 SP1.  Is there a place to get the correct information about DNN caching, its caching settings, etc. ?

No proxy - it's all on a local private development network.  PC workstation plugged into a 1Gbit switch with the server plugged into the same switch.  There is also a third server which is the domain controller, DNS server and WINS Server.  All workstations and servers are setup with static IPs like 192.168.X.X .  The DNS server has local Host A records for the DNN portal website domains and each domain is setup for each website under the sites' Admin settings.  All network machines authenticate as part of the AD domain.

If AJAX is enabled in a DNN portal (at the site level and/or by a module like Ultra Media Gallery 5.4) - is there any other packs, packages, or components that need to be installed on the server in terms of web server or .NET add-ons to support the AJAX features?  It's like certain requests to either the database or IIS itself aren't being completed - or are being cached by the server and not written to the DNN portal database as changes or updates.