I tracked it down to adding a new macro. Reading IR's release notes, I found this for version 6.15:
I had originally created this config using an older version of IR that put the Macros ahead of SpecialProtocols. I could remove a couple of the protocols that come with Ext2 that I'm not currently using, but it's still going to be slower than it was before (since I do use several custom protocols).Modified the order in which the KeyMove section is written when rows are moved within any of the AdvCode-related grids. In the prior version the order was: KeyMoves, Macros, SpecialProtocols, Favs. The new order is: KeyMoves, SpecialProtocols, Favs, Macros. This change will allow people with certain extenders to more easily use the special protocol functions.
Is there any way to make IR use the old order KeyMoves, Macros, SpecialProtocols, Favs? If it's not possible with current versions of IR, are older versions available somewhere?