Wavelet packet in Wavelet toolbox

I have been trying to use the Wavelet Packet 1-D through wavemenu in
the Wavelet toolbox of MATLAB version 6.5. I analyze a signal that i
load to the GUI, but when i click on one of the elements of the tree,
i get the following error message in the main window of MATLAB and
the message "wait... computing" in the GUI:
----------------------------
??? Error using ==> set
Bad value for axes property: 'XLim'
Values must be increasing and non-NaN.

Error in ==>  C:\MATLAB6p5\toolbox\wavelet\wavelet\wpt
reeop.m
On line 573 ==> 		 set(WP_Axe_Pack, ...

??? Error while evaluating text ButtonDownFcn.
-------------------------------------
This does not happen with any of the example analysis signals that
are available with MATLAB.
How can I solve this problem?
Thanks in advance.