image issue after switching my forum from a shared to vps

[techman41973]

I have a PHPBB forum and just ran into a serious issue after my host switched me from a shared server to a VPS, and they can't figure out how to fix it for me.
On all of my posts that contained inline attached pictures, the pictures no longer display, instead if I get a hyperlink to the image.
When I hover over the hyperlink, I see the following http://www.mydomain.com/forum/download/file.php?id=58
If I paste it directly into the browser, I get the following error message generated by file.php
"Unable to deliver file."
However, if I post a new topic, attach an image and place the image inline, the image shows fine inside the post.
I'm not sure what went wrong and how I can resolve this issue.
Thank you

[soumik]

The attachments in the files directory probably do not have the correct permissions/ownership and cannot be accessed by the PHP process.

You need to go into the files directory, look at the owner:group and permissions of the attachments you recently uploaded and apply them to the older attachments.

[Oyabun1]

If the image attachment files were transferred using FTP in ASCII mode rather than binary then they are probably broken.