I dont know specifically why with ELK but I have seen that with Kwikset, Tripplite, Honeywell, GE etc in the past few months.
Many manufacturers are having difficulty getting some components (it only takes one to not be able to make a product).
I know where I work we are seeing up to 50 weeks lead time on some components from some manufacturers in China mostly due to labor and power shortages. Obviously no end product mfg will wait that long and are probably doing what we are doing and evaluating equivalent components from other sources to use. That process can take weeks to evaluate and then get parts.
Quick example we could not get a red LED that we use in a couple of keypads. We were out of production for a few weeks on those models before we could test and get inventory from another mfg (we had 2 or 3 sources and all were out of stock for months). Imagine something more critical then an LED such as a micro which could take months to evaluate.
Like I said I dont know why you are seeing what you are seeing from ELK but I know that a lot of mfg's are struggling with various problems beyond their control. The disaster in Japan will compound those problems for the next year or so.