There's a big problem with melody dictation, in fact, it is so big, that I wonder why anybody has complained about it yet. I know this problem since I purchased EarMaster, but I've been to lazy to complain about it

Is not actually a bug, but instead is more a missed user requirement.
I will try to explain it. I'm going to use four note scales for easier illustration, but it can be applied to 8 notes scales as well.
Look at this scales:
C D E F: This would give me a melody with a major sound.
C Db E F: This would give me a melody with a phrygian sound.
C D Eb F: This would give me a melody with a minor sound.
C D E F#: This would give me a melody with a lydian sound.
Now, where's the problem?
I start melody dictation, for the major scale and i get this:
C E D E C D
Ok, is a mayor melody.
Now I start the exercise with the lydian scal, and I get this:
D E C D E C
That's major too! EarMaster did well, it made a melody from the scales tones, but it failed in giving me a lydian melody!
Now I start the exercise for the minor scale:
C F D F D C
Major again!
And what about phrigian:
C F E E C F C
Another major melody.
How often does this happen? A lot!!! I practice with a 7 melody note, and I have this problem a lot of times.
With larger scales it gets even worse, sometimes I'm practicing with a major scale, and I get a melody that sounds like derived from a pentatonic scale!
So, in order to fix this, EarMaster scales, should have the concept of "key scale tones", that is, the tones that give a melody the sound of a particular scale. For instance, in the previous example, the scales would have this key tones:
C D Eb F: Eb
C D E F#: F#
C Db E F: Db
Major doesn't really need key tones, as any melody without Eb, F# or Db will sound like major. Now EarMaster will generate melodies that always have the key tones at last once (Notice that on 7 notes scales, the key tones will be more than one).
EarMaster let's you input your own scales, so the the key tones can't be harcoded. One should be able to enter an scale, and the key tones for that scale.
Problems don't stop here. Look at this melody
C F D A G E B
Now this can be a melody generated from either:
C major
D dorian
E phrygian
F lydian
G myxolidan
A minor
B locrian
Even with key tones it is not clear on wich scale is based, and the melody will probably sound like mayor, as is the thing the ear is more used to.
To fix this, an alternative, is to play a bass note with the root, that is, if E is played while you hear the melody, it will tend to a phrygian sound, if A is played, it would tend to a minor sound, and so on.
This two features combined (key notes, and bass root note), give an unambigous melody that clearly has the intended sound of a given scale.
And besides all this, there's actually a bug on the melody dictation exercise. I have added about 25 scales, but EarMaster only shows about 20 of them to choose in the exercise.