???imtool errors???

Hallo all experts,

I just learn to use "Image processing toolbox", and start with
following codes:
myim = imread('fehler.PNG');
imtool(myim);
However errors pop up:
??? Undefined command/function 'im2double'.

Error in ==> imuitools\private\makeToolbarIconFromPNG at 39
icon = im2double(icon);

Error in ==> imtool>createToolbar at 723
contrastIcon =
makeToolbarIconFromPNG(fullfile(iconRoot,'tool_contrast.png'));

Error in ==> imtool at 219
hToolbar = createToolbar; % must be called after declaring
navigationButtonGroup

Error in ==> test at 4
imtool(myim)

Since the directory of im2double is contained in the Set Path, it
seems quite strange that I come across such errors.

I have also tried
myim = imread('fehler.PNG');
imshow(myim)

Errors come still:
??? Undefined command/function 'iptgetpref'.

Error in ==> imshow at 151
initial_mag = iptgetpref('ImshowInitialMagnification');

Error in ==> test at 3
imshow(myim)

Are they due to some compatibility problem? My version is listed as
below:

----------------------------------------------------------------------
---------------
MATLAB Version 7.0.4.365 (R14) Service Pack 2
MATLAB License Number: 78139
Operating System: Microsoft Windows XP Version 5.1 (Build 2600:
Service Pack 2)
Java VM Version: Java 1.5.0 with Sun Microsystems Inc. Java
HotSpot(TM) Client VM
-------------------------------------------------------------------------------------
MATLAB Version 7.0.4 (R14SP2)
Simulink Version 6.2 (R14SP2)
Communications Blockset Version 3.1 (R14SP2)
Communications Toolbox Version 3.1 (R14SP2)
Control System Toolbox Version 6.2 (R14SP2)
Fixed-Point Toolbox Version 1.2 (R14SP2)
Genetic Algorithm Direct Search Toolbox Version 1.0.3 (R14SP2)
Image Processing Toolbox Version 5.0.2 (R14SP2)
MATLAB Compiler Version 4.2 (R14SP2)
Neural Network Toolbox Version 4.0.5 (R14SP2)
Optimization Toolbox Version 3.0.2 (R14SP2)
Signal Processing Blockset Version 6.1 (R14SP2)
Signal Processing Toolbox Version 6.3 (R14SP2)
SimMechanics Version 2.2.2 (R14SP2)
Simulink Fixed Point Version 5.1 (R14SP2)
Virtual Reality Toolbox Version 4.1 (R14SP2)
Wavelet Toolbox Version 3.0.2 (R14SP2)

Any advice is highly appreciated,

win2s