Hey, I'm really sorry this took so long to follow up with. Shortly after shipping 1.4.8 it was discovered that raising the connection limit had been broken.
http://code.google.com/p/memcached/wiki/ReleaseNotes149 ^ that and a small number of other things have been fixed in 1.4.9. If you've installed 1.4.8 and ever intend to raise the connection limit above the default, you should upgrade immediately. No other major bugs have been reported in the meantime, and I added a few small notes there. NOTE; 1.4.9 is *not* what 1.4.9-beta1 was. At this point, 1.4.10 will be the performance release. I've pushed over 10 billion requests through what's in the 14perf tree at rates of over 1.2 million keys/sec sustained. I still have a few important things to stress test before I mark it final, but that could happen within the next week. have fun, -Dormando