I've set the Account Lockout Policy to unlock accounts after a period of time - at this point ACT! works again. (I did use "actdiag" to reset the sa password at this point, too - not sure if I needed to or not.)
I noticed that when the account unlocked, I started getting failure messages again (about 1 per minute). 1 user had been logged in to TS for some time - when they logged out, the failure messages stopped. Suspect, therefore, that the problem is TS related.
Looking at Task Manager, each user is running the following processes:
The System user is running:
Suspect that I'm getting problems because a process contains "stale credentials" for the "actadmin" database account.
Please can you help with this? (We're due to install a 20 user system on a customer's TS in a few weeks & I want to be confident that it will continue to work)