jumping plane Europe airports.......

I had install a new texture airport Naples,Italy yesterday,and I was taking off from Rome,on the runway my plane started to jump up and down,the same happened at landing.I tried a few other airports in Europe,the same problem.I have Fs9 installed on another pc, replaced the Scenary-erw-scenary folder but the problem is there,then I did a takeoff from the 2pc and the jumping is there as well,normally I use Sud American airports.Is this a bug,a new problem,something normal? Is there a solution? the scenery is Napoli Capodichino LIRN 2006 v1.3,the talk about this problem::Q: After the installation of LIRN 2006 v1.3, my airplane have strange jumps before entering runway or it not stands correctly on apron.A: Close FS2004. Open the rar file and manually copy AP951170.BGL and FL951170.bgl files in Scenery\eurw\Scenery folder of your FS9, overwriting when requested. Reboot FS2004. Be sure that You don't have any copy of the AF2_LIRN.bgl file, except the one contained in Addon Scenery\Napulevola_LIRN_2006\Scenery.I did the changes,but as I sed before,no solution,on the other pc I never installed the scenary,so it has to be some other thing,I will appreciate any help.Thanks.