Sorry, Deanna, I can't help with your question, but did you get your clematis locally, & if so, where?

Let me put it this way... the first year I planted Crystal Fountain I accidentally chopped it while weeding into a 6 inch stump! No leaves, no nothing but a stick! Really, it was an accident! That was in summer 2008.
The next spring it came back alright. It came back with a vengence! It is now my fullest, best bloomer I have!
Clematis love rough treatment.
How far apart are they planted? Really close? Could be the other one sucking all the nutrients from CF maybe? You may need to keep it fertilized a little more often.
Have you had any blooms this season yet? If so, then after bloomtime chop it to a 6 inch stump! :)
As far as switching positions goes, I don't know anything about Autumn Joy so I can't say much about that except if you decide to move them around just keep them both well watered. Water, water, water! I would ease up on the fertilizer then until they both get over being moved.
Others may have differing opinions, but I say go ahead and do what you need to do!
Here's a pic of my Crystal Fountain this season and it's still growing like nuts! I plan to chop all of mine this season after bloomtime to a 6 inch stump!
Here's a pic of her the first year after planting:

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Here's a pic of her this season so far (11 days ago anyways lol) She actually is climbing farther up the wires but I haven't been able to take a pic of that yet.

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Thanks, kentstar.

nhbabs, I got my in Farmington at Cameron's Garden Center. If you're interested I'll call them to confirm that they sell Crystal Fountain, but here's a picture of a bloom. I has not fully opened but it was suggested that it was Crystal Fountain and it looks like a good match to me. Let me know if it doesn't look like Crystal Fountain!

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Are you sure the stronger clem is Autumn Joy? There is no clem by that name listed on 'Clematis on the Web.' Would guess it may be Sweet Autumn which is a very vigorous plant and will overtake your other clem quickly. Suggest you do a search for 'Sweet Autumn' on this site, you will get lots of info. Also, google 'Clematis on the Web' for additional info.

Sorry, yes it is 'Sweet Autumn', that is my mistake. Will do a search now. I bought it because it was supposed to be highly fragrant.

In that case, I would definitely think about moving the Sweet Autumn or at least the Crystal Fountain away from the SAC! It can get huge! Check out some of the pics of Sweet Autumn on the plant files here. Wow! I just planted one of those last fall and hope mine can get that big!

Should I move Sweet Autumn this week? Late last fall I stepped on the main woody stem so this year it's small as it started growing from new shoots from the roots. If it's OK I'd like to get it moved sooner rather than later.

I called the nursery and they do sell Crystal Fountain, so I'm pretty sure that's what the blue one is and my photo coloring (taken with an iPhone so not the best color sensors) is off.

nhbabs, I'll be swinging by there later this morning. They have a couple left if you'd like one.

Yes, that is Crystal Fountain.

Yes, you should move Sweet Autumn. Sweet Autumn can get to twenty or thirty feet and it does not play well with others.

Do it now.

Sorry, correction! Not the plant files here but on that other site Dave's Garden. Whoops, I am on both so frequently that I sometimes forget where I am lol!

Cathy