I gave a presentation in Feb. at the Rocky Mountain Microbrewing Symposium on brewing better Belgian-style beers and a component of the talk was on making your own invert sugar/candi sugar.
Here's a link to where you can get the powerpoint presentation. It's under "download 2009 presentations HERE!"
There are a number of files in the zipped folder, the one you want to look for is called abbey-saison.ppx. The bit on sugar is a few pages into the presentation.
I've experimented quite a bit and have found that making your own invert and adding it to the boil helps. Plus the small amount of acid added to split the sugar is negliable.
Hope it helps,
Shamrock Brewing Co.