G98: consistency failure



 Hi, all,
 I'm trying to use BLYP/6-311g** to calculate the thermodynamic properties of
 polyacetylenes (C2H2 to C20H2 or even higher with respect to the number of
 carbons). The job is terminated shortly after it is started and gives a
 "consistency failure #2 in CalDSu" message in the log file. I changed
 the
 basis set to 6-311g and use SCF=QC and it still does not work.
 Any suggestion is appreciated.
 Thank you very much.
 Regards,
 ning
 The last part of the log file is
  Requested convergence on RMS density matrix=1.00D-08 within  64 cycles.
  Requested convergence on MAX density matrix=1.00D-06.
  Integral accuracy reduced to 1.0D-05 until final iterations.
  Problem detected with inexpensive integrals.
  Switching to full accuracy and repeating last cycle.
  Warning!  Spurious integrated density:
  NE=   74 NElCor=    0 Integral=    0.00000 Tolerance=1.00D-03
  Consistency failure #2 in CalDSu.
  Error termination via Lnk1e in /usr2/g98/l502.exe.
  Job cpu time:  0 days  0 hours  0 minutes 38.5 seconds.
  File lengths (MBytes):  RWF=   19 Int=    0 D2E=    0 Chk=    1 Scr=    1
 The input file is:
  $ RunGauss
 %mem=8000000
 %Chk=C12H2.chk
 # BLYP/6-311G FOpt SCF Geom=(NoDistance,NoAngle)
 C12H2
 0 1
   C    0      x1               y1               z1
   C    0      x2               y2               z2
   C    0      x3               y3               z3
   C    0      x4               y4               z4
   C    0      x5               y5               z5
   C    0      x6               y6               z6
   C    0      x7               y7               z7
   C    0      x8               y8               z8
   H    0      x9               y9               z9
   C    0      x10              y10              z10
   C    0      x11              y11              z11
   C    0      x12              y12              z12
   C    0      x13              y13              z13
   H    0      x14              y14              z14
   x1       -0.323
   x2       -0.323
   x3       -0.323
   x4       -0.323
   x5       -0.323
   x6       -0.323
   x7       -0.323
   x8       -0.323
   x9       -0.323
   x10      -0.323
   x11      -0.323
   x12      -0.323
   x13      -0.323
   x14      -0.323
   y1       -0.264
   y2        0.948
   y3        2.160
   y4        3.372
   y5        4.584
   y6        5.796
   y7        7.008
   y8        8.220
   y9        9.310
   y10      -1.477
   y11      -2.689
   y12      -3.901
   y13      -5.113
   y14      -6.203
   z1       -0.067
   z2       -0.067
   z3       -0.067
   z4       -0.067
   z5       -0.067
   z6       -0.067
   z7       -0.067
   z8       -0.067
   z9       -0.067
   z10      -0.067
   z11      -0.067
   z12      -0.067
   z13      -0.067
   z14      -0.067
 --link1--
 %Chk=C12H2.chk
 #P RBLYP/6-311G** GEOM=ALLCHECK GUESS=READ Freq
 C12H2
 0 1