[R] Error: value of 'SET_CXTAIL' must be a char or NULL, not a 'char'

[Søren Højsgaard]

Dear List 
On windows XP using R.2.6.2 I get the message 
 
Error: value of 'SET_CXTAIL' must be a char or NULL, not a 'char'
 
in connection with calling C code (using the .Call interface). I have been unable to find any info on this (in Writing R extensions). Can anyone help me with understanding this error? (In case it helps in tracking the problem: I pass two matrices and a list of several matrices to my C function).
 
Regards
Søren