I download qt-sdk-linux-x86-opensource-2009.02.bin to “userxxx/download” , $cd download，into the dictionary.
According to Qt prompt
keyin chmod u+x qt-sdk-linux-x86-opensource-2009.03.bin
keyin ./qt-sdk-linux-x86-opensource-2009.03.bin

then system display：
Installer payload initialization failed. This is likely due to an incomplete or corrupt downloaded file.

I don't know where is my error?

Thank you