It sounds like something's not set up properly in your version of ad.tcl, or that it's not being sourced by your nsd.tcl file when you fire up AOLserver.
The "non-numeric arg to &&" error is an indication that a blank was returned when it tried to pick up a value using ad_parameter, leading to a statement like 'if { "" && something }" or 'if { $something && "" }'.
