diff --git a/tconfpy.py b/tconfpy.py
index bd1408b..49a6a6a 100755
--- a/tconfpy.py
+++ b/tconfpy.py
@@ -6,7 +6,7 @@
 # Program Information
 
 PROGNAME = "tconfpy"
-RCSID = "$Id: tconfpy.py,v 1.131 2004/03/24 08:47:55 tundra Exp $"
+RCSID = "$Id: tconfpy.py,v 1.132 2004/03/24 09:33:44 tundra Exp $"
 VERSION = RCSID.split()[2]
 
 # Copyright Information
@@ -225,14 +225,15 @@
 
 # Messages
 
-Messages["eBADCOND"]    = FILENUM + "Bad '%s' Directive. %s"
-Messages["eBADSYNTAX"]  = FILENUM + "Syntax Error.  Statement Not In Known Form"
-Messages["eCONFOPEN"]   = FILENUM + "Cannot Open The File '%s'"
-Messages["eENDIFEXTRA"] = FILENUM + "'" + ENDIF + "' Without Matching Condition"
-Messages["eENDIFMISS"]  = FILENUM + "Missing %d" + " '%s' " % ENDIF + " Statement(s)"
-Messages["eEQUIVEXTRA"] = FILENUM + "Only a single '%s' Or '%s' Operator Permitted" % (EQUIV, NOTEQUIV)
-Messages["eIFEXTRATXT"] = FILENUM + "Extra Text On Line.  '%s' Only Accepts Variable References As Arguments"
-Messages["eVARUNDEF"]   = FILENUM + "Attempt To Reference Undefined Variable '%s'"
+Messages["eBADCOND"]     = FILENUM + "Bad '%s' Directive. %s"
+Messages["eBADSYNTAX"]   = FILENUM + "Syntax Error.  Statement Not In Known Form"
+Messages["eCONFOPEN"]    = FILENUM + "Cannot Open The File '%s'"
+Messages["eDESCRIPTBAD"] = "API Error: Bad Descriptor Passed For Variable '%s'"
+Messages["eENDIFEXTRA"]  = FILENUM + "'" + ENDIF + "' Without Matching Condition"
+Messages["eENDIFMISS"]   = FILENUM + "Missing %d" + " '%s' " % ENDIF + " Statement(s)"
+Messages["eEQUIVEXTRA"]  = FILENUM + "Only a single '%s' Or '%s' Operator Permitted" % (EQUIV, NOTEQUIV)
+Messages["eIFEXTRATXT"]  = FILENUM + "Extra Text On Line.  '%s' Only Accepts Variable References As Arguments"
+Messages["eVARUNDEF"]    = FILENUM + "Attempt To Reference Undefined Variable '%s'"
 
 
 ###########
@@ -264,12 +265,6 @@
 
 
 #----------------------------------------------------------#
-#             Object Base Class Definitions                #
-#----------------------------------------------------------#
-
-
-    
-#----------------------------------------------------------#
 #               Utility Function Definitions               #
 #----------------------------------------------------------#
 
@@ -362,7 +357,18 @@
     # Add any passed symbols to the SymbolTable
 
     for sym in InitialSymTbl:
-        SymTable[sym] = InitialSymTbl[sym] 
+
+        des = InitialSymTbl[sym]
+
+        # Make sure a valid descriptor was passed for each variable
+
+        if isinstance(des, VarDescriptor):
+            SymTable[sym] = des
+
+        # Invalid descriptor passed
+        else:
+            ErrorMsg("eDESCRIPTBAD", sym)
+            return (SymTable, ErrMsgs, WarnMsgs, DebugMsgs, LiteralLines)
 
     # Parse the file