Irregular/Slow Read Speed from NV+ over Gigabit

Happily, i am now getting a pretty solid 17MB/s write to and 45MB/s read from my NV+ over basic wired GigE (same hardware as above). The only change is that i did a fresh install of OS X Snow Leopard 10.6 last month. I could possibly boost that just a bit with Jumbo Frames and a few other tweaks. So as i suspected, there seemed to be either a bug or errant setting in Finder/OSX or something buried in my 3-year-old installation of 10.5 on my MacBook Pro that was causing the terrible performance.

Sadly, i've encountered a deal-breaker bug in Snow Leopard with no cure (random logouts with an external display attached and/or the graphics card is stressed), so i am forced to revert back to 10.5.

Though it would be so much easier to just roll back to my disk image backup of 10.5 before i upgraded, i think it's worth the effort to try a clean install of 10.5 to see if it's a 10.5 vs 10.6 issue or just something i picked up along the way causing my slow NV+ performance.