Comment on "Strongly correlated Fractional Quantum Hall line junction"
  Physical Review Letter {\bf 90}, 026802 (2003) by U. Z\"{u}licke 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 $\nu_{j}=1/(2m_j+1)$, $j=1,2$; $m_j=0,1,...$. 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. 
Vadim V. Ponomarenko and Dmitri V. Averin