We survived for almost 9 days without a crash, as I was running through and checking tables on a separate slave to try and isolate the bad table(s), but the server ended up dying yesterday morning with a different assertion error that mirrors what you anticipated: 

130106  6:25:34 [ERROR] Index PRIMARY of brandX_affiliate/stats_daily#P#p90 has 4 columns unique inside InnoDB, but MySQL is asking statistics for 5 columns. Have you mixed up .frm files from different installations? See http://dev.mysql.
com/doc/refman/5.5/en/innodb-troubleshooting.html

130106  6:25:34  InnoDB: Assertion failure in thread 139967370213120 in file ha_innodb.cc line 6845
InnoDB: Failing assertion: ut_strcmp(index->name, key->name) == 0
InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.5/en/forcing-innodb-recovery.html
InnoDB: about forcing recovery.
06:25:34 UTC - mysqld got signal 6 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed, 
something is definitely wrong and this may fail.
Please help us make Percona Server better by reporting any
bugs at http://bugs.percona.com/

key_buffer_size=33554432
read_buffer_size=131072
max_used_connections=144
max_threads=500
thread_count=13
connection_count=13
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1126896 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x88d0c5e0
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 7f4cb161ae58 thread_stack 0x40000
/usr/sbin/mysqld(my_print_stacktrace+0x35)[0x7ab8b5]
/usr/sbin/mysqld(handle_fatal_signal+0x4a4)[0x6874b4]
/lib64/libpthread.so.0(+0xf4a0)[0x7f4f6b7884a0]
/lib64/libc.so.6(gsignal+0x35)[0x7f4f6a942885]
/lib64/libc.so.6(abort+0x175)[0x7f4f6a944065]
/usr/sbin/mysqld[0x81c984]
/usr/sbin/mysqld[0x82496b]
/usr/sbin/mysqld[0x82570d]
/usr/sbin/mysqld(_ZN7handler7ha_openEP5TABLEPKcii+0x3e)[0x6898ce]
/usr/sbin/mysqld(_ZN12ha_partition4openEPKcij+0x565)[0x9662f5]
/usr/sbin/mysqld(_ZN7handler7ha_openEP5TABLEPKcii+0x3e)[0x6898ce]
/usr/sbin/mysqld(_Z21open_table_from_shareP3THDP11TABLE_SHAREPKcjjjP5TABLEb+0x58c)[0x6049bc]
/usr/sbin/mysqld(_Z10open_tableP3THDP10TABLE_LISTP11st_mem_rootP18Open_table_context+0xc53)[0x556713]
/usr/sbin/mysqld(_Z11open_tablesP3THDPP10TABLE_LISTPjjP19Prelocking_strategy+0x4
8d)[0x55742d]
/usr/sbin/mysqld(_Z20open_and_lock_tablesP3THDP10TABLE_LISTbjP19Prelocking_strategy+0x44)[0x557e74]
/usr/sbin/mysqld(_Z12mysql_insertP3THDP10TABLE_LISTR4ListI4ItemERS3_IS5_ES6_S6_15enum_duplicatesb+0xc2)[0x579ce2]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x14d8)[0x58a9b8]
/usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x333)[0x58e0e3]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x15cd)[0x58f75d]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0xd7)[0x629c27]
/usr/sbin/mysqld(handle_one_connection+0x51)[0x629d61]
/lib64/libpthread.so.0(+0x77f1)[0x7f4f6b7807f1]
/lib64/libc.so.6(clone+0x6d)[0x7f4f6a9f570d]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (7f4aee425eb0): is an invalid pointer
Connection ID (thread ID): 37454010
Status: NOT_KILLED

So I think I'm getting closer, though I ran a check table on that table and it passed. I rebuilt the table with ALTER TABLE stats_daily ENGINE=InnoDB just to clean up any issues that did exist with it.