FormBuilderLocator with generic type can't always be found

manifest.toString() in vendForm() can return surprising results depending on the field(...) call in the screen.

Sample project here: https://github.com/pbrant/generic_fbl_test / git://github.com/pbrant/generic_fbl_test.git

The cause appears to be the generic valConversion() validation method

Original thread here http://groups.google.com/group/liftweb/browse_thread/thread/af21b61154c2b8c2#