If anybody have any suggestions that would be fantastic, I seem to have exhausted every avenue! I'm using the Tascam US 1641 and Ableton Live. I am not permitted to post URLs here as of yet due to site restrictions, but if you do a quick Google search you can find the product on the Tascam site along with the list of drivers/firmware that I have been struggling with. With the hardware, all inputs/outputs are seemingly fine, everything appropriately connected, all volumes turned up (headphones, mixer etc.). I dont think the problem is with the hardware itself. I installed the latest possible US 1641 driver and firmware from the downloads page on the site. The Mac system settings are showing that the input from the interface is being received. Also, when I try recording on Garageband it both picks up the signal and records successfully. This would suggest that the problem lies with Ableton, however I've selected the US 1641 as the Input and Output in the Ableton Preferences with no luck. No input signal in the Audio track. I checked that the track was active (ie. that I'd hit the red button at the bottom so as to record). The firmware is telling me that the input signal is either 'unavailable' or that there is 'no input signal' which leads me to believe it's a problem with the firmware itself. I tried downloading the latest version of the firmware but it refuses to write, so I downloaded the next down the line which wrote successfully. Could this be the problem? I'm also wondering if it's appropriate that I downloaded the driver for Mac OS X Snow Leopard (the latest driver listed for Macs in the list)? Anyway, I wrote to customer service and they haven't gotten back. Shitballs eh? Googled around extensively and it seems I'm not the only Mac user with this problem. There seemed to be no actual solutions on those forum discussions however, which why I'm throwing it to you guys.