There isn't very much good information about the effect of Arc Fault Circuit Interrupters (AFCIs) on the X10 signal. It is thought that some brands of AFCIs have noise traps that will absorb the X10 signal, but it isn't practical to switch to another brand of AFCI as that would mean replacing the entire panel. Even if you were willing to do that, there isn't any guarantee that the new brand of AFCI will be any better. Installing noise filters are of no help as the filtering is happening right inside the circuit breaker.
You could try installing a Coupler/Repeater (CR), and it will certainly help, but if your breaker panel is full of AFCIs, it may still absorb most of the signal generated by the CR and you may still have problem modules.
The only option I can think of that is guaranteed to work is a powerline firewall (see
Firewalls for more information), but they are very expensive and difficult to install and don't support X10 extended commands.
If you decide to try a CR and you still have one or two problem circuits, you could make your own firewall for those circuits by isolating them from the AFCI with an in-line noise filter and then linking the X10 signal with a second CR. To do this you will need to use CRs that can be linked together such as the ACT CR-234. You might also be able to use the CR-134 to link 3 circuits. I have never tried anything like this, so I can't guarantee that it will work, but it should. If you want more information on what I mean, let me know.