Index: packages/paszlib/src/zstream.pp
===================================================================
--- packages/paszlib/src/zstream.pp	(revision 9334)
+++ packages/paszlib/src/zstream.pp	(working copy)
@@ -300,6 +300,8 @@
 function Tdecompressionstream.seek(offset:longint;origin:word):longint;
 
 begin
+  if (origin = soFromBeginning) and (offset = 0) then
+    Source.Position := 0;
   if ((origin=sofrombeginning) and (offset>=raw_read)) or
      ((origin=sofromcurrent) and (offset>=0)) then
     begin
