Incredibly weird issue

Jeetus Maximus

Hi folks,
Ill dive straight in with this one as Ive been working on it since 9am today, with little progress.
I have USER A who's account locks out without them even being logged into their machine. The user changed their password yesterday as per company policy and since then it keeps locking out after 3-5 minutes.
Platform - WIN 7 Pro 64 Bit
Server - Win Server 2008 R2 Standard

I have done the following -
Cleared credential manager - NO DIFFERENCE
Reset IE and cleared personal details during reset - NO DIFFERENCE
Tested by logging onto another machine - NO JOY
Recreated their login profile - NO DIFFERENCE
Checked for logged on terminal services accounts - NONE LOGGED IN
Connected devices ie. iPad, iPhone, Android - NONE
I have checked on our DC's and have found the following -
- System
- Provider
[ Name] Microsoft-Windows-Security-Auditing
[ Guid] {54849625-5478-4994-A5BA-3E3B0328C30D}

EventID 4776

Version 0

Level 0

Task 14336

Opcode 0

Keywords 0x8010000000000000

- TimeCreated
[ SystemTime] 2014-01-14T12:43:53.301501000Z

EventRecordID 2042599718

Correlation

- Execution
[ ProcessID] 516
[ ThreadID] 29720

Channel Security

Computer XXXXXXDC02.XXXXXXXXXXXXXX.co.uk

Security

- EventData
PackageName MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
TargetUserName USER A
Workstation XXXXXXXX
Status 0xc0000234
Kind of hit a brick wall now. Any ideas anyone?

tier~

Try giving the Account Lockout Status Tool a try.

Does this individual have any apps or services on their machine that would have been manually configured with their old credentials? A connection to a fileshare? Sharepoint portal?

You've hit most of these but this blog post should fill in any gaps to check: Troubleshooting Active Directory account lockout issues « MSExchangeGuru.com