I have come to the conclusion that all applets are dysfunctional...

Question

So yeah, I made my applet, and it is supposed to move an object by giving it a velocity in pixels per millisecond, and starting an animation loop, which moves it for 5 seconds.
So I do this, and everything is working fine after about an hour of coding. Then I decide to touch up my sprite image. I wanted to make it transparent, so I open up Photoshop, and do that. Now it doesn't work. Before I edited the image, the object would move to the edge of the screen, the game would check the boundary, and then reverse the velocity, so it stayed on screen. Now, when you tell the object to move, I can see that the x and y coordinates are changing, but the thing doesn't change on screen.
The applet itself is behaving very weird:
http://img62.exs.cx/img62/7140/whatswronghere9ur.gif
In the first frames, the applet loads up like normal, but there is supposed to be a button there, which no longer shows up.
In the second and third one, it shows that if you cover any part of the applet, it turns white, and just dissapears.
In the 4th one is what happens when you click where the throw button is supposed to be. What prints to the console are the x and y coordinates. So you can see the arrow is just supposed to move back and forth.
I just can't seem to understand why this worked intially but when I changed the image(not the path, I just opened it up and deleted the white background), the thing stopped working. I put everything back to normal, and it still won't work.
The main portion for the code of the applet is this:
http://www.freewebs.com/nickv360/problem/Physics.java
Here are the other classes(Which I didn't write BTW, so no credit to me for them)
http://www.freewebs.com/nickv360/problem/Sprite.java
http://www.freewebs.com/nickv360/problem/Animation.java
Those two classes along with the AnimationLoop algorithm were taken from a book, so yeah.
Can anyone tell me what happened here? (ALSO I'm not sure if this is in the right place, so if it's not, just point me in the right direction).

Answer 1

The only thing that changed was the size of the
image. I made it a bit smaller. But after seeing
that it didn't work, I changedthe image size back,
with no luck however. I am using the java sdk1.5 ,
the latest one. I find it humorous that you won't
believe me, even though I am telling the truth. I
mean, there's nothing more to say on this. I've got
no reason to lieI do not believe that anyone accused you of being a liar, but expressed some doubts towards your conclusions.
The fact of the matter is that lots of people post their problems here and blame it on java itself ('java is broken') etc... and more often than not, the problem lies in their code.
I guess the next thing to do would be for you to post your code here.