Citrix profiles loosing file association

Has anyone had a problem where applications in a citrix session loose the file associations? e.g. user happily working in Outlook over Citrix, then attempts to open an attachment – and file association has been lost, “windows can’t open…” etc. Also, strangely they loose signatures? This even occurs for admin account which is using a local only profile, all others are roaming with 2003 AD profiles. 2 load balanced servers of Metaframe XPa FR3 sp3, latest client. getting userenv 1020 errors in event logs for reg access but can’t track source – possibly related. Have installed UPHClean to handle logoff. Any ideas appreciated.