Windchill DS wont start as a service

Hey All

We have been running Windchill for a while and have it installed with Windchill Directory Service (WDS).

WDS has always run fine being installed as a Windchill Service but for some reason after a restart on Monday Evening Windchill DS Service would no longer start

In the end I had to remove it as a windows service and start it manually and this got the users back on line and running

Has anyone else come across this problem and resolved it

We're on Windows 2008r2 Servers

Thanks in advanced

CJ