Windows 7: Tascam us 144 and machine issue

Hello I am new to this forum and hope someone could help with an issue in have.
So I have a native instruments machine and a tascam us 144 external sound card.
All drivers are installed and the device is working fine. The issue I have is that as I select the tascam as my default device in the audio options for record and play back there is no wave form being registered when the device plays. I mean the little EQ bar is grey and no signal. But it does work. This concerns me because I then use Sony sound Forge pro 10 to record live sets and my turntable running through my soundcard. I select the tascam in sound Forge but no signal comes through to record.
I know this sounds confusing but I hope someone could help out.
Thanks

I have a recording studio (using Sonar X2).

When I use my audio recording devices with Sonar, I only set the device in Sonar, I don't do anything with the sound panels. I have a Roland Octa-Capture and an MAudio Fastrack Ultra 8R (both USB connected). They have ASIO drivers and I just select the unit I want to use in Sonar. The devices show up in the sound control panel but I do nothing with them.

However, some PC sound playback does not work through the devices. e.g. when I use Goldwave (an audio editor) I have to use my PC's sound card and speakers. It won't work through my audio interface unit and studio monitors or headphones.

Thanks for the reply. I will have a look at Native Instruments specs.