Tbl iformat Rowi

Greetings,

It seems that lout throws errors if a table has rows that reaches the
alphabet 'i'. Please try to compile the attached tbli.lout file.

If I run:
    lout -S tbli.lout > /dev/null

It will give:
   18,17: body parameter of @Tbl must be enclosed in braces
   18,25: symbol @Cell unknown or misspelt
   18,35: symbol @Cell unknown or misspelt
   18,45: symbol @Cell unknown or misspelt
   18,55: symbol @Cell unknown or misspelt
   20,17: symbol @Rowa unknown or misspelt
   21,17: symbol @Rowb unknown or misspelt
   22,17: symbol @Rowc unknown or misspelt
   23,17: symbol @Rowd unknown or misspelt
   24,17: symbol @Rowe unknown or misspelt
   25,17: symbol @Rowf unknown or misspelt
   26,17: symbol @Rowg unknown or misspelt
   27,17: symbol @Rowh unknown or misspelt

Removing both 'iformat' and 'Rowi' will solve the problem, but it's
unexpected. Is this a bug?

Thank you,
Robin