Application SQL statement causes hang

Hi,

I have some weird behaviour occurring both in our application and SQLPlus.

Our application executes the following statement during start up:

SELECT EXTENSION_TYPE_ID, TYPE_NAME, SCHEMA_DATA FROM EXTENSION_TYPE where type_name like '%MS Message%';

When this statement is executed both in the application and via SQLPlus, it hangs and never returns.

This statement..:

SELECT * FROM EXTENSION_TYPE where type_name like '%MS Message%';

...returns correctly, as do the following:

SELECT EXTENSION_TYPE_ID FROM EXTENSION_TYPE where type_name like '%MS Message%';

SELECT TYPE_NAME FROM EXTENSION_TYPE where type_name like '%MS Message%';