diff --git a/decode3.f90 b/decode3.f90
index ceb2f7c04..337dda67a 100644
--- a/decode3.f90
+++ b/decode3.f90
@@ -59,6 +59,7 @@ subroutine decode3(d2,jz,istart,filename)
        ps0,npkept,lumsg,basevb,rmspower,nslim2,psavg,ccf,Nseg,        &
        MouseDF,NAgain,LDecoded,nspecial,ndf,ss1,ss2)
   close(23)
+  if(basevb.le.-98.0) go to 999
 
 ! See whether this file should be saved or erased from disk
   if(nsave.eq.1 .and. ldecoded) filetokilla=''
diff --git a/fivehz.f90 b/fivehz.f90
index f3f795a39..3d04666c2 100644
--- a/fivehz.f90
+++ b/fivehz.f90
@@ -84,15 +84,11 @@ subroutine fivehz
   endif
   ibuf000=ibuf
   iwrite000=iwrite
-
   nsec=Tsec
-
   ntr=mod(nsec/trperiod,2)             !ntr=0 in 1st sequence, 1 in 2nd
 
   if(ntr.ne.ntr0) then
      ibuf0=ibuf                        !Start of new sequence, save ibuf
-     ibuf0=ibuf0-2                     !Tweak the Rx start time
-     if(ibuf0.lt.1) ibuf0=ibuf0+1024
 !     if(mode(1:4).ne.'JT65') then
 !        ibuf0=ibuf0+3                  !So we don't copy our own Tx
 !        if(ibuf0.gt.1024) ibuf0=ibuf0-1024
diff --git a/longx.f b/longx.f
index c0e4c069e..844f814af 100644
--- a/longx.f
+++ b/longx.f
@@ -124,5 +124,5 @@ C  Finally, decode the message.
          if(nc.le.47) msg(i:i)=c(nc+1:nc+1)
       enddo
 
- 20   return
+      return
       end
diff --git a/mtdecode.f b/mtdecode.f
index 948d97a85..338d1aae6 100644
--- a/mtdecode.f
+++ b/mtdecode.f
@@ -21,7 +21,6 @@ C  Decode Multi-Tone FSK441 mesages.
       character*90 line
       common/ccom/nline,tping(100),line(100)
 
-!      slim=10.0*log10(10.0**(0.1*MinSigdB)+1.0)
       slim=MinSigdB
       wmin=0.001*MinWidth * (19.95/20.0)
       nf1=-DFTolerance
diff --git a/spec2d.f b/spec2d.f
index 06635c558..c0df82ac5 100644
--- a/spec2d.f
+++ b/spec2d.f
@@ -44,6 +44,10 @@ C  Accumulate average spectrum for the whole file.
 	      psavg0(i) = psavg0(i)+ real(c(i))**2 + imag(c(i))**2
 	   enddo
 	enddo
+	if(sum.eq.0.0) then
+	   sigma=-999.
+	   go to 999
+	endif
 
 C  Normalize and save a copy of psavg0 for plotting.  Roll off the
 C  spectrum at 300 and 3000 Hz.
@@ -120,5 +124,5 @@ C  Find average of active spectral region, over the whole file.
 	enddo
 	sigma=sum/(44*nz)
 
- 	return
+ 999	return
 	end
diff --git a/wsjt.py b/wsjt.py
index 89c940248..4fd987e84 100644
--- a/wsjt.py
+++ b/wsjt.py
@@ -1,4 +1,4 @@
-#-------------------------------------------------------------- WSJT
+#------------------------------------------------------------- WSJT
 from Tkinter import *
 from tkFileDialog import *
 import Pmw
diff --git a/wsjt1.f b/wsjt1.f
index c0e87f70d..9f8d6e210 100644
--- a/wsjt1.f
+++ b/wsjt1.f
@@ -125,6 +125,7 @@
 	enddo
 	avesq=sq/jz
 	basevb=dB(avesq) - 44    !Base power level to send back to GUI
+	if(avesq.eq.0) go to 900
 
 	nz=600
 	nstep=jz/nz
@@ -196,7 +197,8 @@
 	   enddo
 ! For waterfall plot
 	   call spec2d(dat,jz,nstep,s2,nchan,nz,psavg,sigma)
-	   if(jz/11025.0.lt.3.9) go to 900
+	   if(sigma.lt.0.0) basevb=-99.0
+	   if(jz/11025.0.lt.3.9 .or. sigma.lt.0.0) go to 900
 
 	   f0=1076.66
 	   if(NFreeze.eq.1) f0=1076.66+mousedf
@@ -249,6 +251,8 @@
 	dtbuf=nstep/11025.0
 	stlim=nslim2                !Single-tone threshold
 	call spec2d(dat,jz,nstep,s2,nchan,nz,psavg,sigma)
+	if(sigma.lt.0.0) basevb=-99.0
+	if(sigma.lt.0.0) go to 900
 	nline0=nline
 	STfound=.false.
 	npkept=0