SCM error: Multiple instances of label in problem to update

Dear all, I am running the SCM tool in PsN but I am getting the following error: "Multiple instances of label [P]_ in problem to update, ambiguous parameter matching by label. at C:\Perl64\site\lib/PsN_4_2_0/model.pm line 3424." This is a 2 compartment model with oral absorption (ADVAN 4) parameterized in CL and Q (i.e.: TRANS 4) with lag time. Here is the scm config file: model=125_COV.ctl directory=scm-both-125 search_direction=both only_successful=1 parallel_states=1 p_forward=0.05 p_backward=0.01 continuous_covariates=WTKG,HTCM,BMIKGM2,AGEYR,TBILIUM,ASTUL,ALTUL,GGTUL,ALPUL,CRUM,BUNMM,UACUM,UPGL,ECRCL categorical_covariates=SEXF do_not_drop=WTKG,HTCM,BMIKGM2,AGEYR,TBILIUM,ASTUL,ALTUL,GGTUL,ALPUL,CRUM,BUNMM,UACUM,UPGL,ECRCL,SEXF missing_data_token=-99 linearize=0 nm_version=default retries=2 threads=4 [test_relations] CL= SEXF,WTKG,HTCM,BMIKGM2,AGEYR,TBILIUM,ASTUL,ALTUL,GGTUL,ALPUL,CRUM,BUNMM,UACUM,UPGL,ECRCL V2= SEXF,WTKG,HTCM,BMIKGM2,AGEYR,TBILIUM,ASTUL,ALTUL,GGTUL,ALPUL,CRUM,BUNMM,UACUM,UPGL,ECRCL [valid_states] continuous = 1,5 catagorical=1,2 Many thanks in advance for your help. Amir