As others have pointed out, there are any number of cures for the problem, but if it's any consolation, I can reproduce your findings under NT/AS 5.6.1, so it looks very much like a bug in AS as jmcnamara couldn't under Linux.

It might be worth reporting. Likely or not they would say that if you fix your code, you won't have the problem, but it might get investigated and fixed for the next release.