Hm. I don't have any experience with compound bows. Where do you buy your supplies? If you get them at an Archery supply shop, they may be able to help you more. If you don't get your stuff from an Archery supply shop, you might want to see if you can find one somewhat near you. Check your local yellow pages and see what you can find.
Good luck. Sorry I can't be of more help.
~ Joy ~

I don't shoot a compound, but I do know that if the arrows are not intended for the draw weight of the bow they will either shatter (if the arrow "spine" is too light) or simply drop like logs (if the arrow "spine" is too heavy). "Spine" is how much force, or draw weight an arrow can handle; if your bow is set to 25 lbs. draw weight the arrows should be matched to it with a spine of 20-30 lbs. It could be that the cedar arrows you stated with were too light in spine...

First of all, you should work on getting your "form" down to something that is comfortable for you. Don't worry so much about putting arrows in the center of the target until your form is steady and consistent. Practice your draw, being sure to bring your string hand to the exact same place EVERY time you draw (this is called your "anchor point"); be sure to hold the bow in the same place EVERY time you draw; hold the bow the same way EVERY time; lastly, when you release the string, do not pull back further ("plucking" the string) as doing so will only tend to throw off your aim. Shooting form is paramount to good shooting and placing arrows where you want them go. Having a good, matched set of arrows made up for your bow and your draw length helps, too.

Take your bow to a reputable shop (preferably one run by someone who actually shoots bows) and have it "tuned in" by someone who knows how to do it.

Good luck with the archery!

--Artúr Dúbh Maca'Gobhaínn - Archer/Fletcher

Some folks like to use a "kisser button" so they get a consistent 'anchor point'.

How are you aiming without a sight?
Do you use any kind of stabilizers at all?
(I'm just curious on those last two. You seem to have no problems with your aim... )

Sounds like you're doing pretty well already.

First, if you're shooting through your target, consider going to a home supply store like home depot and getting yourself a straw bale to put behind your target. Wheat straw bales are only a couple of bucks, as in 2-3 dollars US, and don't weigh that much. Plus, when you shoot them up, you can use them as mulch.
Secondly, try paper tuning your bow. you'll need to make or buy a frame to shoot through. Usually when you make one, it's wood. make it about 50-60 centimeters across and tack some paper in the open space. Newsprint works well. Just like a painter's canvas. Then, shoot through the paper using your best form.
this will give you an indicator of how your arrows are traveling and what forces are acting upon them since the paper will show a cartoon like opening of the arrow's shape after it passes through.
Compounds must be tuned this way to acheive maximum accuracy. So, don't put it off...
A perfectly tuned bow will leave a hole that looks like an exact representation of the diameter of the arrow shaft, fletchings, and that's it. A hole that is torn, exaggerated, etc, will indicate where you need to tune the rest, nocks, plunger, etc.
This will also show you how much sloppy shooting form can make a difference in how much an arrow can porpoise, spiral, or weave as opposed to true flight that comes from good form.
I realize that this is a very generic reply, so if you need more info feel free to ask.