I think I'm out of luck.
All payments are done to the encrypted wallet but I have 4000 movements and the wallet.dat backup it's from movement 0.
The problem here is the backup it's too old and it doesn't has the addresses with the incomings

good to know for the next time.
Mystery solved. Remember the default keypool is 100 tx. So you need to make backups at least once every 100 txs (I would say once ever 50 to be safe). You can however extend the keypool. For example bitcoind -keypool=2000 would make the keypool 2000 and reduce the frequency of backups (at the expense of a larger wallet).
In time hopefully the reference wallet will go to a deterministic model. Unique random private keys are simply to "fragile". It is to easy to lose coins. A deterministic wallet would always be safe if the seed is saved or backed up.