diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 565b14f6c4..4149d3803b 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -16,6 +16,24 @@
    The license applies to all entries newer than 2009-04-28.
 */
 
+2011-09-20 17:12 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
+  * include/hbapi.h
+  * src/rtl/hbrandom.c
+    + Changed Harbour's core pseudo-random generator from STD C rand()/srand()
+      to superior implementation. New implementation fixed MT problems with 
+      the standard solution on certain targets (f.e. win/mingw, win/msvc)
+      Based on Przemek's patch which is in turn based on algorithm by 
+      Steve Park: http://www.cs.wm.edu/~va/software/park/ suggested by me 
+      on the list. Further modifications:
+         * HB_RANDOMINTMAX() adapted. Checkme, I'm not sure about this.
+         * HB_RANDOMSEED() updated.
+         + headers cleaned, copyright updated, note added
+         + automatic seed defaulting like in previous version (checkme, 
+           we may as well drop it, though it will be create incompatibility)
+         ; per-thread seed didn't work well for me (even with new engine) 
+           so I didn't implement it.
+         + added proto for hb_random_seed()
+
 2011-09-20 13:56 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
   * src/rtl/teditor.prg
     ! fixed following issue: in MEMOEDIT() insert mode the word wrap inserts
diff --git a/harbour/include/hbapi.h b/harbour/include/hbapi.h
index aa6a80ca05..a394367066 100644
--- a/harbour/include/hbapi.h
+++ b/harbour/include/hbapi.h
@@ -968,6 +968,7 @@ extern HB_EXPORT char *    hb_strRemEscSeq( char * szText, HB_SIZE * nLen ); /*
 extern HB_EXPORT char *    hb_numToStr( char * szBuf, HB_SIZE nSize, HB_MAXINT nNumber );
 extern HB_EXPORT double    hb_numRound( double dResult, int iDec ); /* round a number to a specific number of digits */
 extern HB_EXPORT double    hb_numInt( double dNum ); /* take the integer part of the number */
+extern HB_EXPORT void      hb_random_seed( HB_I32 seed );
 extern HB_EXPORT double    hb_random_num( void );
 extern HB_EXPORT void      hb_random_block( void * data, HB_SIZE len );
 extern HB_EXPORT double    hb_numDecConv( double dNum, int iDec );
diff --git a/harbour/src/rtl/hbrandom.c b/harbour/src/rtl/hbrandom.c
index 7e8d541473..761fe2049d 100644
--- a/harbour/src/rtl/hbrandom.c
+++ b/harbour/src/rtl/hbrandom.c
@@ -3,9 +3,10 @@
  */
 
 /*
- * xHarbour Project source code:
+ * Harbour Project source code:
  * Random number generator routine
  *
+ * Copyright 2011 Przemyslaw Czerpak <druzus / at / priv.onet.pl>
  * Copyright 2003 Giancarlo Niccolai <gian@niccolai.ws>
  * www - http://harbour-project.org
  *
@@ -53,11 +54,17 @@
 #include "hbapi.h"
 #include "hbdate.h"
 
-#include <stdlib.h>
-#include <float.h>
+/* NOTE: core random generator algorithm is the work of Steve Park
+         http://www.cs.wm.edu/~va/software/park/
+ */
 
-/* Globally available data, no need to MT it */
-static volatile HB_BOOL s_fInit = HB_FALSE;
+#define MODULUS    2147483647 /* DON'T CHANGE THIS VALUE                  */
+#define MULTIPLIER 48271      /* DON'T CHANGE THIS VALUE                  */
+#define DEFAULT    123456789  /* initial seed, use 0 < DEFAULT < MODULUS  */
+#define MAXIMUM    0xFFFFFFFF
+
+static HB_BOOL s_fInit = HB_FALSE;
+static HB_I32  s_seed  = DEFAULT;
 
 /*
  * HB_RANDOM
@@ -120,32 +127,45 @@ HB_FUNC( HB_RANDOMINT )
 
 HB_FUNC( HB_RANDOMSEED )
 {
-   srand( HB_ISNUM( 1 ) ? ( unsigned ) hb_parni( 1 ) : ( unsigned ) hb_dateMilliSeconds() );
+   hb_random_seed( HB_ISNUM( 1 ) ? ( HB_I32 ) hb_parni( 1 ) : ( HB_I32 ) hb_dateMilliSeconds() );
+
    s_fInit = HB_TRUE;
 }
 
 HB_FUNC( HB_RANDOMINTMAX )
 {
-#if RAND_MAX > HB_VMLONG_MAX
-   hb_retnd( RAND_MAX );
+#if MAXIMUM > HB_VMLONG_MAX
+   hb_retnd( MAXIMUM );
 #else
-   hb_retnint( RAND_MAX );
+   hb_retnint( MAXIMUM );
 #endif
 }
 
 /* Returns a double value between 0 and 1 */
 double hb_random_num( void )
 {
-   double d1, d2;
+   const HB_I32 Q = MODULUS / MULTIPLIER;
+   const HB_I32 R = MODULUS % MULTIPLIER;
+
+   HB_I32 t;
 
    if( ! s_fInit )
    {
-      srand( ( unsigned ) hb_dateMilliSeconds() );
+      hb_random_seed( ( HB_I32 ) hb_dateMilliSeconds() );
       s_fInit = HB_TRUE;
    }
 
-   d1 = ( double ) rand();
-   d2 = ( double ) RAND_MAX + 1.0;
+   t = s_seed;
+   t = MULTIPLIER * ( t % Q ) - R * ( t / Q );
+   if( t <= 0 )
+      t += MODULUS;
+   s_seed = t;
 
-   return d1 / d2;
+   return ( ( double ) t / MODULUS );
+}
+
+void hb_random_seed( HB_I32 seed )
+{
+   seed %= MODULUS;
+   s_seed = ( seed <= 0 ) ? seed + MODULUS : seed;
 }