This affects all php binaries which do not have the symbol "php_json_encode". This includes EL5 and EL6 based linux distributions
The library cannot load because the symbol is not found. Disabling using this symbol also means preventing views from functioning (as well as JSON serialization).
I'd like to note that this is not our bug and not our fault. We are probably not the only extension relying on php_json* functions, and package creators (specifically redhat) should expose this symbol.
Additionally, our configure script checks to see if the PHP_JSON_* constants are defined (and if not, compiles out the relevant code from views - this would make views not work, but not prevent the library from loading).
In any event, we should find a way to work around this, as this bug has been seen quite a bit.
One possible solution would be to call the php-level json encoding function. It may incur a bit of overhead from calling into php, but the function itself is more likely to be there.