slinger, ssi and post

I use slinger with the options -s (enable the SSI commands) -e (enable the
SSI exec command) -d (for debugging).

All my SSI commands work fine until I submit a CGI POST FORM (the datas
are received by the cgi script).
After, for each SSI comands I have the following message in the debug:

Feb 14 03:46:48 nto slinger[634894-2]: Could not start SSI exec script
mycmd: No such file or directory

Please help…

Thanks,

Michel NINET