The Application Enhancer (APE), SIMBL as well as InputManagers are being used to modify programs and system programming interfaces by infiltrating them at runtime and executing code in their context. InputManagers are especially prone to causing instabilities in applications as they are loaded into every application - regardless of whether the InputManager was developed to modify that or another app.
Stability problems did disappear permanently in 100% of all support cases after users, who had such hacks installed, deinstalled them.
Please understand, that we can't offer you support for systems modified in this fashion. We recommend the deinstallation of said hacks for optimal stability.
The hacks are usually found in these locations:
APE: /System/Library/SystemConfiguration/ApplicationEnhancer.bundle (~)/Library/PreferencePanes/ApplicationEnhancer.prefPane (~)/Library/Application Enhancers/ SIMBL: (~)/Library/Application Support/SIMBL/ InputManagers: (~)/Library/InputManagers/