If I recall well your email is at free.fr, so I will asume that you are french (as me). The title in french is 'Etoile Garde à vous', and it was wrote by Robert Heinlein. In english the title is Starship trooper.
a french URL on Heinlein can be found at
http://rocbo.chez.tiscali.fr/Max/sf/heinlein.htm
for others english speaking persons, you can at least see the author picture on this URL.
The original book is very distant from the movie. I must say that I was rather deceived by the film. This is not to say that the film is bad, but rather really far from the book.
For example in the initial book, the troopers are elite soldiers which all rely on heavy enhanced robotic armor. They have jump pack, portable tactical missile launcher, and are stuffed with high tech gear. Loosing one trooper is a big loss. In the film, it is laughable. You see hords of soldiers, some armed with small fire arms.
If you look at the intent of Voerheven (sp?), you see an action movie. If you read Heinlein, and know a little bit about why he wrote the book, you understand that it try to depict how horrible is a war, any war. If I recall well the book was aimed partly against the vietnam war.
Well anyway you should read the book. The troopers against bugs encounters are really scary. You really see that even with this powerful and awesome gears, the soldiers are only poor little humans which are governed by primal feelings, like fear and self preservation.