a couple of issues with mythtv

[lime4x4]

I installed mythubuntu. When i click on watch tv i get the following error

Mythtv is already using all available inputs for the channel you selected. If u want to watch an in progress recording, select one from the playback menu. If u want to watch live tv cancel one of the in-progress recording from the delete menu.

the other problem i have is the tv guide isn't being populated. If i go into the guide it shows me nothing at all.
I'm using schedules direct

[newlinux]

Go to Information Center->System Status

What does it say about your tuners?
What tuner cards do you have and how did you set them up?

[lime4x4]

hauppauge pvr 150. When i set it up i selected the hauppauge card

[superm1]

hauppauge pvr 150. When i set it up i selected the hauppauge card
Odds are you either didn't associate it with a video source, or you choose a non MPG recorder in mythtv-setup.