I never had issues with hidden files. All DCI servers run Linux and are aware of hidden files. It's just not 'pretty' if they go into a wide distribution.

If you use a preformatted disc - use Mac OS disc utility to check wether it is MBR or GUID/GPT formatted.

GUID/GPT can cause REAL issues with some servers - to the point that the content vanishes from the disc. Make absolutely sure it uses an MBR partition! If disc utility shows GUID - erase the disc and re-initialise with the MBR option.

- Carsten