Alright, problem resolved with Trey's help this morning! Boiled down to the error message being misleading.

The problem stemmed from a static block within the DBHelper class. It was trying to get some params from the ServletContext that were returning null. When that class was initialized Java pretty much exploded and threw the class not found error. Fixing that within xml files was the eventual resolution. That, and restructuring the class to better report errors in the future.

Many thanks for yours and everyone's help resolving this!