Sounds like you're looking at something wrong. Rather than counting interval spaces let's us look at the actual notes.
C major
C D E F G A B C, OK?
Counting spaces, from C whole step, whole step, half step, whole step, whole step, whole step , half step. OK?
Intervals (calculated from the root, C)
C - D = (major)second
C - E = major 3rd
C - F = perfect 4th
C - G = perfect 5th
C - A = major 6th
C - B = major 7th
Triads built on the major scale
CEG - maj - I
DFA - minor - ii
EGB - minor - iii
FAC - major - IV
GBD - major -V
ACE - minor - vi
BDF - diminished - viio
So to make a NATURAL minor scale, you have to flatten the 3rd and the 6th and the 7th, right?
C D
Eb F G
Ab Bb C, right?
So your interval relationship (again from the root)
C -D = (major) second
C - Eb = minor 3rd
C- F = perfect 4th
C- G = perfect 5th
C -Ab = minor sixth
C - Bb = minor seventh (or flat seventh or dominant seventh)
So your triads
C Eb G - minor - i
D F Ab - diminished - iio
Eb G Bb - major - III
F Ab C - minor -iv
G Bb D - minor - v
Ab C Eb - major - VI
Bb D F - major - VII
much of this is covered in
jazzbo's tutorial, you should poke around a bit.
The other thing that you have to be careful with is using the natural minor scale when you are talking about patterns of resolution in a minor tune, that's why we got the harmonic and melodic minor...