Cant allow pdf file to upload....

Dears,

Seems like lots of strange case find for file uploading.... 😟
Have a form, enable file uploading, and here's the files config @ upload action

file1: pdf-jpg-gif-png-xls-xlsx-doc-docx
file2: pdf-jpg-gif-png-xls-xlsx-doc-docx

Then when I test the form, all filetypes work fine except PDF....
I have tried the file generated by me, and those on http://greyhead.net/, both fails...
It keeps saying file type is not allow....

Any ideas how to solve it?

Best regards,
Wing

Cool, that's work!!!
thanks for your great help~ 😛

Wing