delay in cubase writing audio recording

Hi Cubase forum,

I need help.

I am using a TAscam US122 to record to cubase. I am recording into two audio tracks. One microphone is pointing at the amp, the other is for vocal.

It has all worked fine for about a year now however now when i am recording you can see a lag beginning to happen as cubase writes the audio wave. it seems to pause then rush again to catch up. when i listen back there are parts where the sound drops away even though their is an audio wave of sound that was recorded.

I have tried messing around with the latency settings in device set up as well as the tascom driver settings but no luck.

can anyone help

thanks