I have been an "XBMC-er" for a while, but have never posted here.
I have had a soft-modded Xbox 1.4 for a few years. (My first...picked up the machine from a friend, and used the 007 exploit, with CASH and using Evo-X as my dash.) Stock HDD, and RAM.
It has never really worked correctly. I am constantly getting "script failed" errors, as well as the normal buffering issues.
For a while, early on, I had Navi-X scripts working "ok", but I had the issue where the movies timed out, and you would only get to stream the first half of a film.
I have updated XBMC several times, and am now on 3.3.3...still, nothing really "works". (other than the fact that I can play a DVD, but I could do that before I modded the machine.)
I have read, and read, and read some more...I have researched unto exhaustion. I gave up, and now just use it to play DVD's in my daughter's room.
Recently, I have been determined to get this going correctly... I have read a few decent post's, and this one by Heimdall intrigues me:
1. I have downloaded the disc, and it boots correctly.Heimdall wrote:If you want a completely clean system, here's what you do - but you have to be absolutely certain, because this will get rid of all apps, gamesaves, etc. from the hard drive.
Boot with HeXEn. the Xbox boots, the LED turns red, ~40 seconds later the menu appears. Select option 2.2.4. PAL Xbox, SC gamesave, or option 2.2.7. NTSC Xbox, SC gamesave, depending on where in the world you are. Follow the instructions, including removing the HeXEn DVD and rebooting. Confirm that the Xbox will now boot into the softmod normally.
So far your softmod is properly rebuilt, but your E partition still has all of your old apps, gamesaves etc., so now it's time to get rid of them.
Insert the HeXEn DVD again, and reboot. The Xbox boots, LED turns red, menu appears after ~40 seconds. Select option 8. Xbox Admin, then System - Format Menu - Format E Drive. Confirm that you want to proceed. Once that has finished (it only takes a couple of seconds), select option 2.2.4 or 2.2.7 again (whichever you picked previously), and follow the instructions as you did first time around. Once you have followed all of the instructions and rebooted, you have a completely clean Xbox with a new softmod.
Now for the final step. Reboot with HeXEn, and select option 4.1, install XBMC on E. Next, get hold of the latest XBMC, unzip it, and use FTP to delete XBMC from E:\Apps\XBMC\, then copy the new XBMC folder to E:\Apps\ (i.e. you should end up with E:\Apps\XBMC\, under which you will have 12 folders (from "credits" to "web"), plus 3 files (copying.txt, default.xbe and keymapping.txt)).
Congratulations, your Xbox is now back to a clean, vanilla state with XBMC as an application. If you want XBMC as your dashboard, make sure it works first, then select Xbox Admin - Switch Dashboards. The LED will turn red, UnleashX will restart, and you select Switch to XBMC on E. Once it's finished, reboot and you will have XBMC as your dash.
2. I have successfully "re-modded" my machine...(more than a few times...)
3. I can FTP in to the machine successfully.
4. I have done the XBMC install to E:...except I can not boot to XBMC from the initial Unleash-X dash...I have to go in to Xbox Admin/Applications/XBMC, which seems to be counter productive.
5. After the last "re-install" I have noted that my earlier install of XBMC (3.3.3) is still there, and have concluded that I may need to format E: to get back to square one, as it were...
6. In the Format options, I am getting an "Enter Password" directive...(a password I do not have)
So this leads me to today:
1. Is there a working password? (google and local search has not produced one.)
2. Do I need to format E: per Heimdall's post?
3. How in the hell do I get everything to play nice? (Maybe a different thread)
I appreciate any and all assistance, in advance. As with all of the forums I frequent, everyone here seems to be very helpful, and knowledgeable.
Thanks All...
sorry new myself so no good for other help....
). Two of those plugins dont work for me either, some addons on that repo are not being maintained therefore there are still some broken addons on there 
btw for navi x you should go to script addons, amd download navi x from there, then when you open it (from scripts) it will say error cannot open file, click ok and go right (or left) on the dpad and go to set playlist as home, this should fix it.