The text object below just has to provide the background for the snowflakes, I assume?
You will have to do one of the following:
1. either convert the text to paths (that is both texts), then make the top one a clipping masks
this is bad, since the text is no longer editable
2. Put a rectangle with your desired color behind the snowflakes and clip it with the text, so that you'll have only one textobject. Not two on top of each other.
I don't know if anybody can provide the background why this happens with text as a clipping mask, it just happens.
The text as Clipping path works fine for me. I don't have to convert text to outlines to make a Clipping mask. Can you show us by posting a snapshot what you are trying to get? Also it would be helpful to know the version of Illustrator you are using. Illustrator CS5 has introduced a new way of creating Object clipping masks.
If I understand you correctly after you make this clipping you want the type with the stars to be reposition-able as one unit.
I did the same thing you did except I select the duplicate and original text and the stars all at once then did a command 7.
Here is a video
I would not use those third party plug ins they look like they might be your problem.
Problem is this: two identical text-objects on top of each other, one of them a clipping mask:
It can be clearly seen that they're for some reason not identical anymore.
Solution: avoid this situation:
Why not just place the stars on a background (rectangle or whatever) with the desired solid colour, and then create the one and only Live Type on top and use that as the Clipping Path?