Gpsbabel does not work at all in brand new fedora 15. I have followed suggestions from https://bugzilla.redhat.com/show_bug.cgi?id=713483 and rebuild it from the source .rpm. I have also fixed udev rules, as described here:

## /etc/udev/rules.d/51-garmin.rules
SYSFS{idVendor}=="091e", SYSFS{idProduct}=="0003", MODE="0666"

Now (sometimes) I was able to fetch GPX trace but only as a root.

Inspecting /var/log/messages I noticed suspicious messages from gpsd daemon, ie:

Aug 14 16:50:09 darkstar gpsd.hotplug: gpsd_control(action=add,arg=/dev/ttyUSB0)

Moreover the deamon starts/stops in some tricky way as it is down if one looks in Programs →Administration→Services, but ps uax | grep gpsd indicates something contrary:

nobody  2530  0.0  0.0  12652  1412 ? S<s  13:31  0:00 gpsd -n -F /var/run/gpsd.sock

As gpsbabel works flawlessly in my fc11 w/o gpsd I have decided to remove it:

yum erase gpsd
## removes also following dependencies:
 kdeutils-libs-4.6.5-2.fc15.i686 kdeutils-4.6.5-2.fc15.i686
 kde-settings-kdm-4.6-10.fc15.noarch kdm-4.6.5-2.fc15.i686
 digikam-1.9.0-2.fc15.i686 digikam-libs-1.9.0-2.fc15.i686
 kdeedu-marble-4.6.5-1.fc15.i686 kdeedu-marble-libs-4.6.5-1.fc15.i686
 kdeplasma-addons-4.6.5-1.fc15.i686
 kdeplasma-addons-libs-4.6.5-1.fc15.i686 ktorrent-4.1.1-1.fc15.i686
 ktorrent-libs-4.1.1-1.fc15.i686 kpackagekit-0.6.3.3-2.fc15.i686
 kde-plasma-networkmanagement-vpnc-0.9-0.53.20110616git.nm09.fc15.i686
 kde-plasma-networkmanagement-openvpn-0.9-0.53.20110616git.nm09.fc15.i686
 plasma-scriptengine-python-4.6.5-2.fc15.i686
 kdenetwork-4.6.5-1.fc15.i686 kdenetwork-libs-4.6.5-1.fc15.i686
 kde-plasma-networkmanagement-pptp-0.9-0.53.20110616git.nm09.fc15.i686
 kde-plasma-networkmanagement-0.9-0.53.20110616git.nm09.fc15.i686
 kde-plasma-networkmanagement-libs-0.9-0.53.20110616git.nm09.fc15.i686
 kdebase-workspace-4.6.5-2.fc15.i686
 kdebase-workspace-libs-4.6.5-2.fc15.i686 gpsd-2.95-6.fc15.i686
## and disables the following udev rules:
 ostrzeżenie: /etc/udev/rules.d/99-gpsd.rules zapisano jako
 /etc/udev/rules.d/99-gpsd.rules.rpmsave

Pretty surprising that so many KDE packages depends on gpsd! Now I have access to gpsbabel as normal user. (It needs 10--20 second to plug the device in fc15 while in fc11 it was instantaneously.)

Moreover my Gnome3 desktop once unusable looks much better (I still intend to use Xfce however). It seems KDE in FC15 interfere in a nasty way...

Added 24 august 2011: Xine error while playing .avi file resolved.

$ rpm -qa '*ffmpeg*' 
ffmpeg-devel-0.7-0.3.20110612git.fc15.i686
ffmpeg-libs-0.7-0.3.20110612git.fc15.i686

$ rpm remove ffmpeg-devel
$ yum downgrade ffmpeg-libs

Removed:
ffmpeg-libs.i686 0:0.7-0.3.20110612git.fc15 

Installed:
ffmpeg-libs.i686 0:0.6.90-0.2.rc0.fc15 

xine now works with .avi. Btw:

$ rpm -qa '*git*'
emacs-git-el-1.7.6-1.fc15.noarch
emacs-git-1.7.6-1.fc15.noarch
git-1.7.6-1.fc15.i686

It appears ffmpeg-libs-0.7-0.3.20110612git and ffmpeg-devel-0.7-0.3.20110612git were the only compiled from git shapshots packages installed in my system (providing gip snapshots are always marked by adding git to package name).

It is convenient to add exclude=ffmpeg-libs to /etc/yum.conf to prevent yum to update ffmpeg libs with yum update command.

Added 31 august 2011: According to man xine one can specify ``additional command line arguments'' using ~/.xine/xinerc where each line specifies an additional command line argument. However --geometry 990x650 does not work, as well as -G 990x650. By trial and error I have figure out the only(?) working syntax:

##vi ~/.xine/xinerc
-G990x650

Note no space after -G.