Hi all. We are working on FF NPAPI plugin for a long time, and FF 18 became unstable with our plugin. There no permanent steps to reproduce, but after some time (at least few seconds) FF process got huge memory allocation and after that crash. Can be reproduced only with FF18. After some research we found that this issue related to only one plugin function. In case we change one parameter (used 'ctypes.int32_t.ptr' instead 'ctypes.bool.ptr') it became much more stable. I do not see any reason of this, and i can't find any documentation regarding this behavior. I'll provide any information for further investigation. Hope for your help =) Please do not hesitate for ask =)