Problems with attached files

I have transfered my forum on VPS everything is all right
except there is a little problem
when i upload (with VB) a file bigger than 2Mo there is a pop up message declaring that there is an error,I remark that the maximum limit for uploads PHP is 2MO ,so I raised it to 18 Mo
now the problem is different:
when we upload the file it takes its time but by the end:
1: first time i have this message

2: when i try 2 end, third time
nothing is attached without any messages instead it is ANNOUNCED THAT THE OPERATION HAS FINISHED BUT NO FILE IS ATTACHED.
this happens only with big files
this problem does not exist with the old server

anyone can help

thanx in advance



VB Admin Control Panel

[Ntfu2]

You're script execution timeout is set to low probably. try to up that along with php max post size up to 18MB

hopefully that helps you.