Need help - Merging objects with same fill color causes seams

Hello - I'm new to this forum - I was hoping someone could give me some help with an issue I keep having in Illustrator CS5. I have done many searches for help with this, but I could not find the answer. Sorry if it's been dealt with and I could not find it.

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I'm able to use Pathfinder>Merge to join objects with the same fill color with no problem - but for some reason I often run into issues when my object was created from Expanded text or from an Effect.

As in this case:

I created this image using text with an Outline and the 3D Effect:
Attachment 100662

I Expanded the image's appearance and then Pathfinder>Merge - I want all the deep purple areas to be joined as one object, but you can see the deep purple outline won't join with the other shapes:
Attachment 100663

Here's a closer shot, with the objects unselected so you can see the faint outline where the shapes won't join:
Attachment 100664

Even if I try to get rid of the seam by creating a new object (same fill color) on top, and then Merge that, it just creates another outline. See, here I've created a rectangle on top of the seam and Merged, but the rectangle is still visible:
Attachment 100665

What is the best way for me to flatten this graphic so it doesn't have these seams?

Thanks in advance for any help!

Hi, I'm new here. Haven't had this problem before. But flattening it may solve the problem. I hope that someone will response to you soon because it's my first time to see this problem, too. :(

Try expanding the art before using the pathfinder operations.

Hey onedayteam - I'm using the Pathfinder to Merge the objects, I'm not sure what method you use to flatten objects, but if you have another method please let me know!

Hey mwenz - I did Expand the artwork first - next I Merged. I did try to explain that - sorry if my explanation wasn't clear.

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I'm a long time Illustrator user, I just can't figure out why these objects that use to be outlines are being treated differently than any other shape. I finally had to select each section and manually connect them all with the Shape Builder Tool, which seems like such a waste of time.

If anyone knows why the outline isn't Merging - or has any tips for me to try - PLEASE let me know!

Is it not the stacking order that is causing the problem? I am away from my computers at the moment but when I get back to them I will go through the process and get back to you. This evening UK time.