Howdy!
After a few days of messing around, I was able to get my Prof 7300 working well under Ubuntu 9.10. Here are a few tips:
1. I pulled the motor & switch out of the loop. I was having a bit of a hard time dealing with the motor stuff at first, and it's really something that should debugged last and not first. If you can position your dish manually, verify it via a secondary source (I used a SV360E), then get your LNB/Card setup correctly, you're in a good place to start messing with the motor & switch. Make sure that you can pull out at least some amount of signal properly, without them in the loop, so that you can use verification of this signal as a sign that your switch/motor setup is working properly.
2. This card felt pretty sensitive to LNB settings, which of course, they all should be. But in my case, even though the standard settings that 'scan' and 'w_scan' use are correct, it works when I manually enter the LNB information, and doesn't when I don't. Here is some example usage of scan that pulls properly for me (My LNB is a QPH031 Quad LNBF, and I am attached to linear).
scan -5 -U -l 10750 /usr/share/dvb/dvb-s/IA5-97w
3. If you're having problems with your PCI card, you should be using 'dmesg' to help you debug. If you're asking a question, you should include relevant information from there in your post, just in case. This will confirm that your hardware driver is at least functional.
4. If you have installed MythTV, be sure to turn it off if you're going to be messing around with the command line and other utilities. You can do this via:
/etc/init.d/mythtv-backend stop
(and 'start' to turn it back on later)
5. In MythTV, make sure you specify your LNB properly before a channel scan.
6. The files in '/usr/share/dvb/dvb-s/' aren't always up to date. Verify with Lyngsat, and add information appropriately.
7. If you want to use the IR controller on the card, you will have to de-blacklist the driver. It's blacklisted for a reason, it doesn't seem to work that well. I haven't done any debugging as to why. I can't find the page that have the HAL de-blacklisting instructions, but they are out there somewhere. I was able to get everything working except the 'enter' key, which made it useless. I gave up and moved on to other projects.
8. I found that MeTV is somewhat useful for getting started, but I can't specify the LNB settings for it through the standard interface. But I am able to get one transponder on Galaxy 19 with the defaults, so this could be a good place to start. Also, quit via the file menu and not the 'X' button, otherwise it just hides up in your status panel and keeps hold on the card, which will give you a headache.
I'm not sure how much this applies to the 7301, but I hope it's useful.