I have been using the same IMBC recipe for over a year and in most respects I am quite happy with it (good flavour, workability etc) however, I have a few issues with it and wonder if another recipe would be better.
I would like to have a recipe that remains stable after adding flavourings, fruit purees etc. mine tends to get a bit soft.
I would also like a recipe that might hold up a bit better when it is warmer, I've been having a lot of problems with bulges and sagging in my fondant because of the heat. (Although, maybe this is just a result of using IMBC and no changes will make is more stable in warm weather? I've never had a problem with sagging when the weather is cool)

Here is the recipe I am using:
350 grams sugar
100 mls water
200 mls egg white
907grams butter
I heat my sugar to 125 celcius.

Thanks for your help!

What is the amount of butter you use? I assume you make IMBC and not meringue?

And how much of what sort of flavouring do you use?
IMBC can only hold so much of a liquit, (made on a good recipe) so that can destabelize it.

Ya I guess the butter amount would be important, wouldn't it! I editted my original post to add the butter (907 grams/2lbs)
I've used Lor-Ann flavouring, but I am trying to move toward a more natural approach and add fruit purees, white chocolate, bavarian cream, fruit curds etc. rather then artificial flavouring (I don't think there's anything wrong with that, it just isn't the approach that I would like to take.)
I'd also like to be able to add alcohol or liquers such as champagne or Baileys.

I'm in to the natural approach. I do not like lorann, it has only artificial flavouring, which I don't like myself.

900 grams of butter can have as much as 8 tablespoons of liquid.
You can reduce the alcohol to that amount if you want a better taste of this.

Thank you, that is great information!
So I would think my best bet is to reduce the purees, alcohol etc as much as possible to concentrate the flavour so that I can get a strong enough flavour while only adding a max of 8 tablespoons.

Little, I add a cup or more of puree to my IMBC (recipe for 6 sticks of butter) and can add 1 tbsp alcohol/liquid for each stick. I think your recipe must be too weak.

Mine is Warren Brown's on his Cake Love site. I just gave my changes for mega stable meringue on the meringue thread going on now.

For the weather, I explain to my customers that these cakes cannot sit out, but must need to make a grand entrance closer to cutting and serving time. In every case, the customer agrees because they want the flavor. This may mean adjusting your delivery time.

Butter is butter. Even in stiff meringue, it will act the exact same as a stick sitting on the counter.

Vgcea: I think it is this thread here

http://cakecentral.com/modules.php?name=Forums&file=viewtopic&t=747526&highlight=

SCP: I just looked up Warren Brown's recipe last night and have it book marked to try! To me it looks like my recipe has a more butter to meringue ratio then his does, so hopefully this will fix some of my issues. I'm also going to try your changes as well. Thank you for your help!
Can I just ask at what point you add the egg yolk and corn syrup?