If Navi-x is your only problem then you might want to start by checking in the Navi-x fourms.
http://www.wiimc.org/forum/viewforum.php?f=9
You will find many problems with the Navi-x portal.A user by the name of FDM has made an attempt to fix this.Although I have not tried his project out myself,I have read his post and if his stuff does as he has stated,Then this would be the best thing happen for Navi-x users.When I get some free time I will be trying it out myself.