Index: openacs-4/packages/accounts-finance/tcl/modeling-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/accounts-finance/tcl/modeling-procs.tcl,v
diff -u -N -r1.4 -r1.5
--- openacs-4/packages/accounts-finance/tcl/modeling-procs.tcl	28 May 2010 06:35:03 -0000	1.4
+++ openacs-4/packages/accounts-finance/tcl/modeling-procs.tcl	4 Jun 2010 21:58:03 -0000	1.5
@@ -31,7 +31,11 @@
 } {
     Returns the sign of the number represented as -1, 0, or 1
 } {
-    set sign [expr { $number / double( abs ( $number ) ) } ]
+    if { $number == 0 } {
+        set sign 0
+    } else {
+        set sign [expr { round( $number / double( abs ( $number ) ) ) } ]
+    }
     return $sign
 }