Runaway AppleFileService CPU Cycles

Hi Folks

In a bit of a dilemma here and frustrated that I cannot find the solution:

Setup:

Mac Mini core i7 Server 2x500gb, 16gb RAM, 10.6.8 Server

2 x Promise Pegasus RAID R6 (12TB (2.2tb free) & 18TB(6.8tb free))

AppleFileService

SMB

OpenDirectory (No network user home folders)

Extensis Portfolio Server

60-70 users connect concurrently all 10.9.3 Mavericks, software used Creative Cloud, Office2011 & iWork.

Now to the crux of the situation, each day around 3pm my AppleFileService cpu cycles go off the charts (700%) slowing down browsing of fileshares and file access, it takes a stopping and starting of the service to reset things. I have a number of these installations elsewhere and haven't seen any of the other machines behave this way so it's local to this mini in particular, the only difference with this is Extensis Portfolio.

I was thinking of upgrading to Mavericks server to match compatibility with clients but hesistant to do it just now.

I'm seeing multiple openings from the same ip of a single file (not bundle) so the one IP (client) opening the same illustrator file about 10 times when cpu cycles are at their highest.

Really at my wits end with this as it's been ongoing for about 45 days now.

Any advice and how to properly troubleshoot or even a direction on how to resolve would be greatly appreciated.

Kind regards

Niall