odd ball Sample Volume issues

I'm releasing a new game tomorrow (IOS) and I'm tying up a few loose ends tonight.

ODD BALL ISSUE #1 with sample volumes.

I have 3 sounds, each are MP3 files under 5k each.
I play these samples when one object hits 3 different objects. I'm not using channels.

I'm setting a variable called FXVolume with a slider. This variable can be set between 0 and 100. That value is passed in each of the 3 collision events. I play the sound first, and in the same event I set the volume of the sample to FXVolume.

The sound played when I hit an enemy plays fine. if the FXvolume is low, the sound plays quietly. If the FXvolume is high, the sound is loud.
The sound played when I hit a safe object plays fine. if the FXvolume is low, the sound plays quietly. If the FXVolume is high, the sound is loud.

When the object hits the 3rd object type, which is a collectable object, the sound always plays at full volume. Adjusting the volume of this sample does nothing. I cannot figure out why this is happening. The ONLY thing different is that there are MANY of the collectible objects. Could it be that everything is happening too fast? Well, i tested that, and that is the case. The first one is very quiet but each one after that is full volume. is there any way to resolve this? Players will want to adjust volumes, but quickly repeating sounds are impossible to hush.

Any ideas? Thanks for pondering it with me!

OK, I found a fix. I thought I'd share this with others in case you encounter a similar problem.

1st I created a Global Value called "SoundChannel" and set it to 1 and play the sound on Channel = SoundChannel

Each time the sound plays, I increment SoundChannel by 1. So i'm shifting to a new channel each time. when the SoundChannel = 10 I reset to 1. This worked. Its important to note that setting the volume of the channel must be done in the same event as the "play".