If, on the other hand, you are asking whether the Enhanced 5,23 can be optimized, Alex Kan is is no longer a member of the SETI team and is now doing what was described as a "real job" and unfortunately does not have the time to devote to SETI any longer, as he did in developing the previous optimizations.

However, the new applications will include some - but not all - of the optimisations developed by Alex, and by the equivalent teams working primarily in the Linux and Windows environments. To put it simplistically, the app will include the clever programming techniques (because they apply to every processor), but won't include much of the processor-specific stuff (because it's important to Berkeley that the standard applications run on as wide a variety of CPUs as possible).

As well as running OSX 10.4.10, it is worth making sure you are running the latest version of BOINC Manager. That is 5.10.7 (or even 5.10.10), which are downloadable from the SETI@home website (shown in the menu on BOINC Manager Projects or Tasks pages when an active item is selected)