They all installed it properly using the isxSQLITE.exe installer, right? The patcher that comes with it is required for things to work right. Simply copying isxSQLite.dll into the extensions directory is not acceptable for installing isxSQLite.
If that's not the issue, then it crashes every time there is an update to isxSQLite...or just on the first one?
Don't really know why it would happen -- but if it continues to be a problem I'll try to see where it's happening.