[BRLTTY] CPU load 100% with version 3.8dev and Orca?

[Hermann]

Hello all,
I observed that the CPU load is 100% as soon as I start brltty together 
with Orca. Entering:
top
shows that "us" and "sy" in the CPU line add up to 100%.
A member of the Orca list suggested that switching back to 3.7.2 and 
deinstalling python-pyrex solves the problem.
Is this issue known? Does the use of 3.7.2 without pyrex really matter?
One of the annoying effects of that phenomenon is a swap partition that 
contains 800 MB data after a short time. This makes the system slow down 
and finally unusable till I reboot my machine.
Any ideas?
Regards
Hermann