complete_io does seem to fix some issues... however it raises others:

root@frankenmatt:/benchmarks/waffle_2.0# grep -n "7:1 " /mysql_home/mysql540-waffle/error.log
51:Memcached miss: Block: bf2:7:1 : Thread : 1144666448 time:51 
52:Memcached set: Block: bf2:7:1 : Thread : 1144666448 time:468 
53:Memcached set: Block: bf2:7:1 : Thread : 1144666448 time:8401 
147431:Memcached get: Block: bf2:7:1 : Thread : 1144666448 time:125 
147434:Memcached set: Block: bf2:7:1 : Thread : 1144666448 time:6028 
185727:Memcached (write) set: Block: bf2:7:1 : Thread : 1144400208 time:82 
454229:Memcached (write) set: Block: bf2:7:1 : Thread : 1144400208 time:81 
743017:Memcached (write) set: Block: bf2:7:1 : Thread : 1144400208 time:137 
1559529:Memcached (write) set: Block: bf2:7:1 : Thread : 1144400208 time:77 
2209311:Memcached (write) set: Block: bf2:7:1 : Thread : 1144400208 time:85 
root@frankenmatt:/benchmarks/waffle_2.0# grep -n "7:3 " /mysql_home/mysql540-waffle/error.log
50:Memcached miss: Block: bf2:7:3 : Thread : 1144666448 time:382 
147430:Memcached miss: Block: bf2:7:3 : Thread : 1144666448 time:52 
root@frankenmatt:/benchmarks/waffle_2.0# grep -i -n -b3 error /mysql_home/mysql540-waffle/error.log 
147429-9567137-Memcached miss: Block: bf2:0:2 : Thread : 1144666448 time:0 
147430-9567198-Memcached miss: Block: bf2:7:3 : Thread : 1144666448 time:52 
147431-9567260-Memcached get: Block: bf2:7:1 : Thread : 1144666448 time:125 
147432:9567322:090528 11:45:49  InnoDB: Error: space id and page n:o stored in the page
147433-9567395-InnoDB: read in are 7:3, should be 7:1!
147434-9567435-Memcached set: Block: bf2:7:1 : Thread : 1144666448 time:6028 
147435-9567498-Memcached miss: Block: bf2:7:147 : Thread : 1144666448 time:43 
--
147477-9570174-Memcached miss: Block: bf2:1:27 : Thread : 1144932688 time:51 
147478-9570237-Memcached set: Block: bf2:2:116 : Thread : 1145198928 time:15078 
147479-9570303-Memcached get: Block: bf2:1:1 : Thread : 1144666448 time:126 
147480:9570365:090528 11:45:49  InnoDB: Error: space id and page n:o stored in the page
147481-9570438-InnoDB: read in are 1:3, should be 1:1!
147482-9570478-Memcached set: Block: bf2:1:1 : Thread : 1144666448 time:16129 
147483-9570542-Memcached miss: Block: bf2:3:3 : Thread : 1144666448 time:53 
--
149045-9670798-Memcached get: Block: bf2:1:e8d : Thread : 1147861328 time:153 
149046-9670862-Memcached set: Block: bf2:3:b8f : Thread : 1147062608 time:24442 
149047-9670928-Memcached get: Block: bf2:7:4001 : Thread : 1146263888 time:223 
149048:9670993:090528 11:45:51  InnoDB: Error: space id and page n:o stored in the page
149049-9671066-InnoDB: read in are 7:22621, should be 7:16385!
149050-9671114-Memcached set: Block: bf2:7:4001 : Thread : 1146263888 time:3318 
149051-9671180-Memcached miss: Block: bf2:7:432c : Thread : 1146263888 time:48 
--
174720-11338188-Memcached set: Block: bf2:1:63ca : Thread : 1145731408 time:8270 
174721-11338254-Memcached get: Block: bf2:1:85a2 : Thread : 1145731408 time:161 
174722-11338319-Memcached get: Block: bf2:1:8001 : Thread : 1145731408 time:121 
174723:11338384:090528 11:46:11  InnoDB: Error: space id and page n:o stored in the page
174724-11338457-InnoDB: read in are 1:37219, should be 1:32769!
174725-11338505-Memcached get: Block: bf2:1:7aa0 : Thread : 1144932688 time:279 
174726-11338570-Memcached miss: Block: bf2:3:5dc0 : Thread : 1145731408 time:74