This error happens on custom builds of Android that have a custom version of OI File Manager pre-installed that uses the same package name, but is not signed with the original OpenIntents certificate.
This issue is known for
* CyanogenMod
* Omfgb ROM
* DeFrost ROM
* GummyJAR ROM
* Liquid Smooth Roms
Please contact the maintainers of those distributions for a solution on how to uninstall the pre-installed file manager.
These ROMs ship a custom version of OI File Manager that has the wrong signature, i.e. that is not signed with the original (i.e. OpenIntents) certificate. Ideally, the maintainers should modify the package name so that their pre-installed file manager and our OI File Manager can be installed concurrently on the same device. Until they provide this update, you should first uninstall the pre-installed file manager so that you can install the latest version of OI File Manager.
If you have root access:
1. Remove the OI File Manager apk file from /system/app
2. Install OI File Manager from Market.
Please write to CyanogenMod to take out the old version of OI File Manager from /system/app and only use a version that has been properly signed by OpenIntents:
* Star the following issue report:
http://code.google.com/p/cyanogenmod/issues/detail?id=3805
* Write to this forum:
http://forum.cyanogenmod.com/topic/16205-oi-file-manager-cant-be-updated...