FULL PRODUCT VERSION :
java version "1.5.0_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_04-b05)
Java HotSpot(TM) Client VM (build 1.5.0_04-b05, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
Auto selection/scroll to the item when corresponding key is pressed works for first couple of times and then stops working.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile and run ComboBoxDemo.java (example http://java.sun.com/docs/books/tutorial/uiswing/components/example-1dot4/ComboBoxDemo.java ) with 1.5.x

Press B (auto selects Bird)
Press P (selects Pig)
Press B again the selection doesn't change! From this point onwards it doesn't auto select and won't respond to any character key!
It does respond to arrow keys though!

Works without any problem with versions prior versions.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
When first character is pressed using keyboard JComboBox should auto scroll to that item.
ACTUAL -
Not responding to Key press

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
http://java.sun.com/docs/books/tutorial/uiswing/components/example-1dot4/ComboBoxDemo.java
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Press Up or Down arrow key and then it responds next one or two character key presses and then stops working.

Release Regression From : 1.4.2
The above release value was the last known release where this
bug was known to work. Since then there has been a regression.