InnoDB table locking error (2 replies)

I'm seeing this error in my logs after running a query:
[ERROR] Got error 147 when reading table './epi/epi_qe_meas_values'

Looking up that error, it's:
MySQL error code 147: Lock table is full; Restart program with a larger locktable

The table is using the InnoDB engine, and I have innodb_table_locks set to ON.
I couldn't find any mention of this error in this forum or in the MySQL documentation.
Some pages on the web have suggested turning innodb_table_locks to OFF before running the query, or increasing the innodb_buffer_pool_size.

Any ideas how to fix this?

thanks,
imran