Treeview Won't Load With Dynamic Source

I have an application that loads various directory structures from the network that a user has access to into hierarchical data sources and places each of the structures into Session variables since the amount of directory structures that may be loaded is dynamic per user. When a user clicks to do certain things I have the treeview bind to the proper directory structure. I get the datasources from the Session variables to the page by dynamically loading them into a PlaceHolder when the page initializes. The issue is that it appears that the treeview is binding to the datasource, because it the datasource is empty the treeview comes right up empty, however if the datasource has any data even just a 100 nodes the treeview will never come up the page just keeps processing for several minutes until it times out. Below is some code. Any ideas are appreciated, thanks. I know the datasource is OK though, because if it is not dynamic and I bind the treeview to a datasource that is placed in ...