Horde did not attach file as the file was empty?

[PixyPumpkin]

I am working with PSA v8.0.1 RedHat EL3 and PSA-Horde 3.1.3 and suddenly Horde is not handling attachments any more, I can add an attachment but when I hit send mail I receive the following error:

Did not attach "Filename.jpg" as the file was empty.

Needles to say the file is not empty, does someone know what is going wrong here?

Thx!