This is where we archive common user problems and their solutions. User knows that it was typed in correctly, because they have proofread it thoroughly, or perhaps typed it in more than once. This is true no matter how carefully the user proofreads, or says they do.
Users always overestimate the accuracy of their typing.
No, there are not bugs in these routines. By now they have been thoroughly tested by many thousands of users over many years. For C users, a common problem is attempting to use the routines with arrays declared using native C declarations, rather than using the required Numerical Recipes allocation utilities. This is discussed in the book, pp. For both C and Fortran users, the other common problem is not reading the book carefully, to understand how the input and output arrays are packed.