That comma in the example formula should be a semi-colon.  

NOTE:  The LOOKUP syntax in pop-up guide under the insert menu shows "lookup(0,0,0)"  The syntax example should show the correct delimiter.  i.e.  "Syntax:  LOOKUP(0;0;0".

At least the syntax-example is fixed now (as in , got replaced with ; ). Thanks
for that hint.

SVN commit 592093 by nikolaus:

Functions	Fix "LOOKUP function only returns last value".

BUG: 127411


 M  +3 -3      branches/koffice/1.6/koffice/kspread/kspread_functions_reference.cc  
 M  +2 -2      trunk/koffice/kspread/functions/reference.cpp  


--- branches/koffice/1.6/koffice/kspread/kspread_functions_reference.cc #592092:592093
@@ -253,15 +253,15 @@
   unsigned rows = lookup.rows();
   if ((cols != rr.columns()) || (rows != rr.rows()))
     return Value::errorVALUE();
-  Value res;
-  
+  Value res = Value::errorNA();
+
   // now traverse the array and perform comparison
   for (unsigned r = 0; r < rows; ++r)
     for (unsigned c = 0; c < cols; ++c)
     {
       // update the result, return if we cross the line
       Value le = lookup.element (c, r);
-      if (calc->lower (lookup, le) || calc->equal (lookup, le))
+      if (calc->lower (le, num) || calc->equal (num, le))
         res = rr.element (c, r);
       else
         return res;
--- trunk/koffice/kspread/functions/reference.cpp #592092:592093
@@ -252,7 +252,7 @@
   unsigned rows = lookup.rows();
   if ((cols != rr.columns()) || (rows != rr.rows()))
     return Value::errorVALUE();
-  Value res;
+  Value res = Value::errorNA();
 
   // now traverse the array and perform comparison
   for (unsigned r = 0; r < rows; ++r)
@@ -260,7 +260,7 @@
     {
       // update the result, return if we cross the line
       Value le = lookup.element (c, r);
-      if (calc->lower (lookup, le) || calc->equal (lookup, le))
+      if (calc->lower (le, num) || calc->equal (num, le))
         res = rr.element (c, r);
       else
         return res;

The example is still misleading.  I can't think of a case where the lookup and
results vectors will change.  Lookup implies some kind of a "fixed table".

The example should reflect the fixed position of the table.

 i.e., LOOKUP(C1;$A$1:$A$3;$B$1:$B$3)

Otherwise, I would be interested in seeing an example of a "floating lookup
table".

This bug is still partially living in KSpread 1.6.3.  If the first and second
parameters are text in general formatted cells, the function still returns the
last item in the result vector.  An example follows:
    A            B
2 Isogen        62.46
3 Megacyte   2,782.87
4 Mexallon       25.5
5 Morphite      9,111
6 Nocxium         111
7 Pyerite        4.44
8 Tritanium       3.9
9 Zydrine    2,297.97
...
20 Isogen    =LOOKUP(A20;A2:A9;B2:B9) [result 2,297.97]

When I substitute numbers for the names, it works fine, but with text (either
capitalized or all small) it returns the last item.