I unchecked the BiDi option, mlterm works fine.
As in debbugs #640180, it seems that Bidi processing is a trigger of this bug. I checked my environment and noticed that BiDi processing is enabled. So I turned off the option.
It didn't crash before Oneiric even I checked Bidi option, I hope that maintainer upgrades Oneiric's package.
I unchecked the BiDi option, mlterm works fine.
As in debbugs #640180, it seems that Bidi processing is a trigger of this bug. I checked my environment and noticed that BiDi processing is enabled. So I turned off the option.
It didn't crash before Oneiric even I checked Bidi option, I hope that maintainer upgrades Oneiric's package.