Sometimes I see driver boot failures when memory is exhausted. I am not talking about the normal memory pool the end-users see though, so maybe this has something to do with shared memory?
Here is what I see (as an example): all my partitions are HPFS386 (there are 15 of them), when I am trying a new device driver, often times the HPFS386 cache size (set to 128Meg right now) becomes too large and during boot-up I start seeing HPFS386 disk error messages...well, no errors exist, but during the boot process, whatever changes I implemented caused the available memory for HPFS386 cache to be exhausted, thus the failures.
Another example of this is playing with SNAP allocated video memory amount. The hardware has 256Meg on-board, but I only have it set to use 32Meg, else I run into problems booting various other device drivers.
Sooo...my point being: could what you are seeing be similarly driven by memory availability? Maybe the new AOS drivers are now consuming more?