hello,
i tried to capture a video from my Canon MV730i in kdenlive, but it didn't work; i can capture from kino/dvgrab.
kdenlive see my camera and i can see an image from it, but i can't play or rewind/fforward; when i press pause kdenlive emits only a crackling/looping sound.

-- System Information:
Debian Release: squeeze/sid
APT prefers testing
APT policy: (990, 'testing'), (850, 'unstable'), (10, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.32.8.02202010 (PREEMPT)
Locale: LANG=it_IT.UTF-8, LC_CTYPE=it_IT.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages kdenlive depends on:
ii ffmpeg 5:0.5+svn20100208-0.1 audio/video encoder, streaming ser
ii kdebase-runtime 4:4.3.4-2 runtime components from the offici
ii kdelibs5 4:4.3.4-3 core libraries for all KDE 4 appli
ii kdenlive-data 0.7.7-1 a non-linear video editor (data fi
ii libc6 2.10.2-2 GNU C Library: Shared libraries
ii libgcc1 1:4.4.2-9 GCC support library
ii libmlt++3 1:0.5.0-0.0 MLT multimedia framework C++ wrapp
ii libmlt2 1:0.5.0-0.0 multimedia framework (runtime)
ii libqt4-dbus 4:4.5.3-4 Qt 4 D-Bus module
ii libqt4-network 4:4.5.3-4 Qt 4 network module
ii libqt4-svg 4:4.5.3-4 Qt 4 SVG module
ii libqt4-xml 4:4.5.3-4 Qt 4 XML module
ii libqtcore4 4:4.5.3-4 Qt 4 core module
ii libqtgui4 4:4.5.3-4 Qt 4 GUI module
ii libstdc++6 4.4.2-9 The GNU Standard C++ Library v3
ii melt 1:0.5.0-0.0 command line media player and vide

Versions of packages kdenlive recommends:
ii dvdauthor 0.6.14-4 create DVD-Video file system
ii dvgrab 3.5-1 grab digital video data via IEEE13
ii frei0r-plugins 1.1.22git20091109-1 minimalistic plugin API for video
ii genisoimage 9:1.1.10-1 Creates ISO-9660 CD-ROM filesystem
ii recordmydesktop 0.3.8.1-2 Captures audio-video data of a Lin
ii swh-plugins 0.4.15+1-4 Steve Harris's LADSPA plugins

what can i do?

Check if you have libavc1394-0 installed, otherwise install & try again

yes, it is installed:
libavc1394-0/testing uptodate 0.5.3-1+b2.

no hint?