Here's what I'm seeing using the NETWORKDAYS function as an example:
Neither Analysis ToolPaks loaded - no NETWORKDAYS formula at all
Analysis TookPak only loaded - no NETWORKDAYS formula at all
Both Analysis ToolPaks loaded - Networkdays (sentence case only) available
On my own PC I have the NETWORKDAYS (All caps) function available.
When I add the Analysis ToolPak VBA I get both Networkdays and NETWORKDAYS