diff -durr work.orig/SortKmersImpl.h work/SortKmersImpl.h
--- work.orig/SortKmersImpl.h	2009-08-20 11:25:39.336695499 +0000
+++ work/SortKmersImpl.h	2009-08-20 11:25:51.431932630 +0000
@@ -98,7 +98,7 @@
     {    if ( reads[l].size( ) < KSPAN ) continue;
     unsigned int N = reads[l].size( ) - KSPAN + 1;
     if ( S + 2*N >= R.size( ) ) {
-      unsigned nn = Max( (long unsigned) ( 1.2 * R.size( ) ), (R.size( ) + 2*N) );
+      unsigned nn = Max( (long unsigned) ( 1.2 * R.size( ) ), (long unsigned) (R.size( ) + 2*N) );
       if ( nn < R.size( ) ) FatalErr( "SortKmers<1>: Unsigned-int overflow (R=" << R.size( ) << ")" );
       R.resize(nn);
     }
@@ -180,7 +180,7 @@
 	}
 	if ( q == N ) break;
 	if ( S + 2*N >= R.size( ) ) {
-	  unsigned nn = Max( (long unsigned) ( 1.2 * R.size( ) ), (R.size( ) + 2*N) );
+	  unsigned nn = Max( (long unsigned) ( 1.2 * R.size( ) ), (long unsigned) (R.size( ) + 2*N) );
 	  if ( nn < R.size( ) ) FatalErr( "SortKmers<10>: Unsigned-int overflow (R=" << R.size( ) << ")" );
 	  R.resize(nn);
 	}
@@ -207,7 +207,7 @@
       top += Min( N - top, (unsigned int) 10000 );
       
       if ( S + 20000 >= R.size( ) || S + 2*N >= R.size( ) ) {
-	unsigned nn = Max( (long unsigned) ( 1.2 * R.size( ) ), (R.size( ) + 2*N) );
+	unsigned nn = Max( (long unsigned) ( 1.2 * R.size( ) ), (long unsigned) (R.size( ) + 2*N) );
 	if ( nn < R.size( ) ) FatalErr( "SortKmers<10>: Unsigned-int overflow (R=" << R.size( ) << ")" );
 	R.resize(nn);
       }