struts1 and struts2 together

[Otto, Frank]

hi,
 
I have an old struts1 application. Now, I want to use struts 2 for a new part 
of them (ajax configurator). With the struts 2.0.11 version it work's fine, but 
If I upgrade to struts 2.1.0 snapshot, I will get many errors, especially 
NullPointerExceptions.
 
Is it possible to use struts1 with struts 2.1.x?
 
 
kind regards,
 
Frank