This is related to bug lp:925377, but confirmed on the 5.3.6 release.
Jervin R (viiin) wrote a reproducer which I have attached (myisam_crash.rb) and confirm causes the corrupt table message. We're seeing corrupt tables on our live databases as well.
This bug appears to be present still on 5.3.6 - possibly not during ENABLE|DISABLE keys but immediately before drop. see my.cnf below and Ruby script for test case.
Produces the output:
120426 11:32:39 [ERROR] mysqld: Table './test/customerXX' is marked as crashed and should be repaired