It may be your digital processing board. In direct mode all processing is bypassed. The DVDA mode is automatically direct and you may be able to use multichannel analog outputs from a Bluy-Ray or DVD player for surround sound. Otherwise here is a list of authorized US Arcam repair centers.
http://www.americanaudiovideo.com/support.html
Nick
http://www.americanaudiovideo.com/support.html
Nick