Bug

#!/usr/bin/env python
##################################################
# Gnuradio Python Flow Graph
# Title: Top Block
# Generated: Mon Mar 18 20:21:59 2013
##################################################

from gnuradio import digital
from gnuradio import eng_notation
from gnuradio import gr
from gnuradio.eng_option import eng_option
from gnuradio.gr import firdes
from gnuradio.wxgui import scopesink2
from grc_gnuradio import blks2 as grc_blks2
from grc_gnuradio import wxgui as grc_wxgui
from optparse import OptionParser
import numpy
import wx

class top_block(grc_wxgui.top_block_gui):

    def __init__(self):
        grc_wxgui.top_block_gui.__init__(self, title="Top Block")
        _icon_path = "/usr/share/icons/hicolor/32x32/apps/gnuradio-grc.png"
        self.SetIcon(wx.Icon(_icon_path, wx.BITMAP_TYPE_ANY))

        ##################################################
        # Variables
        ##################################################
        self.samp_rate = samp_rate = 32000

        ##################################################
        # Blocks
        ##################################################
        self.wxgui_scopesink2_0 = scopesink2.scope_sink_f(
            self.GetWin(),
            title="Scope Plot",
            sample_rate=samp_rate,
            v_scale=0,
            v_offset=0,
            t_scale=0,
            ac_couple=False,
            xy_mode=False,
            num_inputs=1,
            trig_mode=gr.gr_TRIG_MODE_AUTO,
            y_axis_label="Counts",
        )
        self.Add(self.wxgui_scopesink2_0.win)
        self.throttle = gr.throttle(gr.sizeof_char*1, samp_rate)
        self.random_source_x_0 = gr.vector_source_b(map(int, numpy.random.randint(0, 256, pow(10,5))), True)
        self.digital_dxpsk_mod_0 = digital.dbpsk_mod(
            samples_per_symbol=16,
            excess_bw=0.35,
            gray_coded=True,
            verbose=False,
            log=False)

        self.digital_dxpsk_demod_0 = digital.dbpsk_demod(
            samples_per_symbol=16,
            excess_bw=0.35,
            freq_bw=6.28/100.0,
            phase_bw=6.28/100.0,
            timing_bw=6.28/100.0,
            gray_coded=True,
            verbose=False,
            log=False
        )
        self.blks2_error_rate_0 = grc_blks2.error_rate(
            type='BER',
            win_size=100,
            bits_per_symbol=1,
        )

        ##################################################
        # Connections
        ##################################################
        self.connect((self.digital_dxpsk_demod_0, 0), (self.blks2_error_rate_0, 1))
        self.connect((self.blks2_error_rate_0, 0), (self.wxgui_scopesink2_0, 0))
        self.connect((self.random_source_x_0, 0), (self.throttle, 0))
        self.connect((self.throttle, 0), (self.digital_dxpsk_mod_0, 0))
        self.connect((self.throttle, 0), (self.blks2_error_rate_0, 0))
        self.connect((self.digital_dxpsk_mod_0, 0), (self.digital_dxpsk_demod_0, 0))


    def get_samp_rate(self):
        return self.samp_rate

    def set_samp_rate(self, samp_rate):
        self.samp_rate = samp_rate
        self.throttle.set_sample_rate(self.samp_rate)
        self.wxgui_scopesink2_0.set_sample_rate(self.samp_rate)

if __name__ == '__main__':
    parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
    (options, args) = parser.parse_args()
    tb = top_block()
    tb.Run(True)