Trueman999
Congratulations on becoming canadian citizen. If you have valid I-94 and H1B paper and cdn citizenship card you should be ok to return to US with your existing Passport of your first nationality, I assume you dont have H1B visa stamp in your other passport. I read here few months ago somebody in the similar situation eneterd USA without any problem.
Would you mind sharing your experience of citizenship test, oath and related process and the time line of events since you mailed your citizenship application to CIS ?