The CSTR database had the following value in variable M36 at position
248: 1,006.10. Apparantly R does not support this notation and converted
   the M36 variable to a factor variable. I looked at the values of the
248th contig, and it really seems to be that the value is 1006.10 so I
fixed this an turned M36 into a numeric variable. As far as I can tell,
this particular instance is the only case where a value gets higher than
1000.