DVB-C: bad receiving on kernel 2.6.28 (64 bit)

DVB-C: bad receiving on kernel 2.6.28 (64 bit)

[Amir Bukhari]

I have before a running box with debain lenny and the kernel 2.6.24 (32 
bit).  I build the DVB from the old multiprotocol source (before more 
than one year). the system has work very well.

now I want to extend my system with new hardwares. the new hardwares are 
worked well on the old lenny system.
I install  xbuntu  (9.04) with the kernel 2.6.28 (64 bit).

my DVB-C cards are got detected (TT-C 1501 and DVB-C 2300 FF).
running scan detect all channels.

then running czap (for testing) I got:
############
czap -a 1 -c channels.zap -n 1 -H

using '/dev/dvb/adapter1/frontend0' and '/dev/dvb/adapter1/demux0'
reading channels from file 'channels.zap'
  1 RTL 2:113000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_64:202:203:12020
  1 RTL 2: f 113000000, s 6900000, i 2, fec 0, qam 3, v 0xca, a 0xcb
status 1f | signal  75% | snr  13% | ber 0 | unc 0 | FE_HAS_LOCK
status 1f | signal  75% | snr  13% | ber 31459 | unc 1383 | FE_HAS_LOCK
status 1f | signal  75% | snr  15% | ber 28906 | unc 1408 | FE_HAS_LOCK
status 1f | signal  75% | snr  14% | ber 29936 | unc 1230 | FE_HAS_LOCK
status 1f | signal  75% | snr  14% | ber 29022 | unc 851 | FE_HAS_LOCK
status 1f | signal  75% | snr  15% | ber 26547 | unc 616 | FE_HAS_LOCK
status 1f | signal  75% | snr  13% | ber 26656 | unc 780 | FE_HAS_LOCK
status 1f | signal  75% | snr  14% | ber 27935 | unc 655 | FE_HAS_LOCK
################

to be sure I compiled v4l-dvb from mercule (recent code from yesterday), 
but I got the same result.

is there any known problem with 64 bit (as my system has worked well on 
32 bit version)?

best regards,
-Amir