Animation Problem: Walk cycle

Ok, here’s a problem I’ve been having, and so far I have been unable to figure out what is going on! Maybe you can help me get this one right?

So, I modelled this mouse, and created an armature for it . I did a walk cycle for it (which I still need to fine tune… ), got to the NLA stageand got the mouse walking in a straight line. So far, so good. My next task of course, was to create a path curve and associate the mouse with it. The result may be viewed here

As you can see, this action resulted in the mouse taking a lying down position.
Then, I performed an “Apply scale and Rotation” (CTRL-A) function on both the curve and the mouse, and the result is a bit wierd: the body aligned properly, but the arms are stretched forward, as can be seen here

WHy is this happening? It beats me. The fingers are parented to little floating bones, to keep them aligned properly, as suggested by Bassam in the Mancandy tutorial. I suspected they could be causing the problem, so Iactually deleted them at one point, but the problem persisted. If you would like to take a look at the .blend file, it is here:

Any help would be much appreciated

Thanks, and best regards to all