dnl remove the cached value and test again
unset ac_cv_lib_$1_$2
AC_CHECK_LIB($1,$2,[
- unset ac_cv_header_`echo $3 | sed "s/[^A-Za-z]/_/g"`
+ unset ac_cv_header_`echo $3 | sed ['s/[^a-zA-Z0-9_]/_/g;s/^[0-9]/_/']`
AC_CHECK_HEADER($3,[EX_CHECK_STATE=YES],[])
],[])
else