I solved it my self, this is what I had to do after install to get XMLTV grabber to work as expected.
Running Ubuntu 12.04 64bit, Core i5, 16 GB ram.
Install TVHeadend, setup you sat card and scan channels and muxes as usual.
Wait for "Muxes awaiting initial scan:" to show '0'
Install XMLTV if you didn't already.
Open a terminal (Ctrl-Alt-T) and:
cd to the /home directory
Run: sudo chown hts hts
Run: sudo su hts
Run: tv_grab_swedb -configure
Choose the default path's when prompted.
Choose to fetch 'All' channels
Run: tv_grab_swedb
(the channels are downloaded)
In TVH set the 'EPG Grabber' like this:
Update channel name: yes
Update channel number: yes
Update channel icon: yes
Internal grabber:
Module: XMLTV: Sweden (tv.swedb.se)
Grab interval: 12
Hours
Hit 'Save configuration' and you will see something like this in the log window:
Feb 22 19:05:30 /usr/bin/tv_grab_se_swedb: grab /usr/bin/tv_grab_se_swedb
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: grab took 1 seconds
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: parse took 0 seconds
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: channels tot= 101 new= 101 mod= 101
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: brands tot= 0 new= 0 mod= 0
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: seasons tot= 0 new= 0 mod= 0
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: episodes tot= 860 new= 860 mod= 860
Feb 22 19:05:31 /usr/bin/tv_grab_se_swedb: broadcasts tot= 860 new= 860 mod= 860
I don't know if this is all the channels because in my Satbox i can see ~1200 channels with two LNB's
Go to the tab 'Electronic Program Guide' and click the 'update' (blue arrow button lower left corner)
And if everything turned out ok the EPG will show for all channels.
Cheers / Conny