Backup/Restore problem. ID don´t change on resource or image links

I'm using a moodle instalation 1.9.4. from 3 weeks ago. I'm having the
following problem:

When restoring a course into a new course, the image and resource links
are broken. Looking the links I can see that it's calling the old course
id, not the new one. For example:

a course with id= 35 have the image links like:
http://avirtual.forempv.ccoo.es/file.php?file=%2F32%2Fimage.jpg, where 32
is the id of the old course from wich I did the backup.

I saw several posts with more or less the same problem, but I could'nt see
any clear solution or could'nt see any explanation that there isn´t a
solution now to this problem. I could'nt find this on the tracker.

I would be glad to know if there is any solution to this, because i and
I'm having to change by hand the id number of all the images and resources.

Thank's in advance