Redis 2.2.11 vs 2.4.9 benchmark comparison

redis-2.4.9-cheap-laptop-benchmark.txt

I was making some presentation and wanted to show how fast Redis is (redis-benchmark), even on cheap laptop - 4GB RAM, 2core, Ubuntu (3.0.0-17-generic #30-Ubuntu SMP Thu Mar 8 20:45:39 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux).

I had Redis 2.2.11 installed then.

The number I got are:
MSET (10 keys) - 81300.81 rps
SET            - 129870.13 rps
GET            - 172413.80 rps 
INCR           - 178571.42 rps
LPUSH          - 166666.67 rps
LPOP           - 172413.80 rps
SADD           - 175438.59 rps
SPOP           - 169491.53 rps 
LRANGE (first 100 elements) - 81300.81 rps
LRANGE (first 300 elements) - 37313.43 rps
LRANGE (first 450 elements) - 26881.72 rps
LRANGE (first 600 elements) - 21186.44 rps

Today I upgraded Redis to 2.4.9 and out of curiosity redid the benchmark.
Then new numbers are:
MSET (10 keys) - 85470.09 rps
SET            - 169491.53 rps
GET            - 172413.80 rps
INCR           - 161290.33 rps
LPUSH          - 175438.59 rps
LPOP           - 169491.53 rps
SADD           - 169491.53 rps
SPOP           - 166666.67 rps
LRANGE_100 (first 100 elements) - 63694.27 rps
LRANGE_300 (first 300 elements) - 23419.21 rps
LRANGE_500 (first 450 elements) - 15673.98 rps
LRANGE_600 (first 600 elements) - 9560.23 rps

====== MSET (10 keys) ======
 requests per second

Most figures show improvement, but LRANGE numbers are much worsen.
LRANGE_100: 81300.81 -> 63694.27
LRANGE_300: 37313.43 -> 23419.21
LRANGE_600: 21186.44 -> 9560.23 rps

Is it to be expected? Is it Ubuntu not doing well here? Can I tune something?