Physical Review Letter 90, 026802 (2003) by U. Zülicke and E. Shimshoni and subsequent extended paper proposed an "exact solution" of the problem of a tunnel junction of length L between two single-mode edges of the Fractional Quantum Hall Liquids with different filling factors ν_j=1/(2m_j+1), j=1,2; m_j=0,1,.... The purpose of this comment is to point out that the solution found in these papers is not correct and to present correct solution of a particular instance of this model.