I'm trying to run tascamUS-1641 with windows 7 64bit and sonar X2 I'm having a allful time

What kind of problem are you having.
Have you installed the driver that came with it....or downloaded the driver from the Tascam site?
 
http://tascam.com/product/us-1641/downloads/
  
If you are having trouble loading the driver...turn the Windows UAC (User Access Control) off....
Control Panel
    User Accounts
          Change User Account Control Settings
                   Move the Slider all the way to the bottom
Windows will then force you to reboot
 
Worked out-of-the-box here...no problems.
 
Hope This Helps

What kind of problem?

I would suggest you set your audio interface to: Sample Rate of 44.1, and an ASIO Buffer Size of 128 (might be expressed as Number of Samples - if so shoot for something that gives you around 9-11 millisecond latency, as a starting point).
 
Once the above is done, power down the interface and back up again.  Please note that all of the above should be done while Sonar is not running.
 
OK, after that, fire up Sonar, and try the following:
 
1.  Go to Preferences>Audio>Playback and Recording, and select ASIO as the driver mode, then click Apply.
 
2.  Now, in Preferences>Audio>Device Settings, make sure the Sample Rate is set to 44.1 - to exactly match what you have set for your audio interface.  Again, click Apply.
 
3.  In Preferences>Audio>Devices, check all inputs and outputs for your audio interface and click Apply.
 
4.  Now go to Preferences>File>Audio Data, and set Record Bit Depth to 24 and again click Apply.
 
5.  Now, preview a sound or song file in the Media Browser, and see if it sounds OK.
 
Please try the above and post back with results.
 
Bob Bone
 

I think you meant awful, not allful, but unless you tell us what you mean by that, we can't help you.