diff -r 42a7b0fff69d linux/drivers/media/dvb/frontends/stb0899_algo.c
--- a/linux/drivers/media/dvb/frontends/stb0899_algo.c	Sat Apr 19 11:27:44 2008 +0200
+++ b/linux/drivers/media/dvb/frontends/stb0899_algo.c	Sat Apr 19 11:30:47 2008 +0200
@@ -1539,14 +1539,16 @@ enum stb0899_status stb0899_dvbs2_algo(s
 
 		/* Store signal parameters	*/
 		offsetfreq = STB0899_READ_S2REG(STB0899_S2DEMOD, CRL_FREQ);
+		if (offsetfreq & 0x20000000) {
+			/* sign extension */
+			offsetfreq |= 0xc0000000;
+		}
+		/* use 64-bit arithmetic to avoid overflow */
+		offsetfreq = (s32)((s64)offsetfreq * 
+		                  ((s64)internal->master_clk / (s64)1000000) / 
+		                  ((s64)((1 << 30) / (s64)1000)));
 
-		offsetfreq = offsetfreq / ((1 << 30) / 1000);
-		offsetfreq *= (internal->master_clk / 1000000);
-		reg = STB0899_READ_S2REG(STB0899_S2DEMOD, DMD_CNTRL2);
-		if (STB0899_GETFIELD(SPECTRUM_INVERT, reg))
-			offsetfreq *= -1;
-
-		internal->freq = internal->freq - offsetfreq;
+		internal->freq = internal->freq + offsetfreq;
 		internal->srate = stb0899_dvbs2_get_srate(state);
 
 		reg = STB0899_READ_S2REG(STB0899_S2DEMOD, UWP_STAT2);