URGENT! - permission errors, need help!

[tjobbe]

An error occurred while creating the order number lock file (../acatalog/OrderLock.num). The error was Permission denied. Actinic ecommerce can not create a unique order number and can not continue. Please contact us directly with your order.

This happens on the chekout process on my site, www.boxes-bags.com, what does it mean?

Also, how do you "replace" all the files on an update of the site?

[Duncan Rounding]

Check the user permissions of the acatalog directory.

[pinbrook]

Also, how do you "replace" all the files on an update of the site?

site REFRESH completely removes the site and reuploads ALL files.

But a refresh will not replace the orderlock.num as this needs to stay to keep continuity of order number

site upload will upload changed files only

[tjobbe]

Turns out my web host has also posted here, his post has more detail: http://community.actinic.com/showthread.php?t=21716

I'm also looking for a developer to help me get the store back up and running, if anyone can help, please get in touch asap!