FULL PRODUCT VERSION :
1.6.0, 1.6.0u1

ADDITIONAL OS VERSION INFORMATION :
Windows XP Professional

EXTRA RELEVANT SYSTEM CONFIGURATION :
JNLP file is located localy, web-server runs locally for the web-start

A DESCRIPTION OF THE PROBLEM :
Apparently the 1.6 java has different approach inside the JNLP classloader.
The performance profiler shows significant amount of time spent
in the java.util.jar.Attributes.Attributes() and
sun.net.www.protocol.jar.URLJarFile.getManifest().
Same web-start app is taking 7 seconds to start under 1.5u11 and
45 seconds under 1.6.x

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create jar file with large number of classes (~1k, 10mb jar), sign it
and launch through the webstart (make sure most of your classes need to be loaded at the very beggining, no extensive operations required).


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
In 1.5 such app would start in few seconds
ACTUAL -
In 1.6 it is much slower

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
None, stay on 1.5 Webstart until it is fixed