SCCM Capture task sequence weird issue

[Sheridan]

We occasionally build a reference image and capture it to deploy using SCCM. Its worked ok in the past and it has been a little while but I tried to capture an old fashioned golden image again with a simply TS that has one task to capture the image to a share (the image is already sysprep'd)

 

However at the capture stage I get an immediate error 0x80070490 which I believe is permissions based

 

So when I edit the TS to check the username and password for access the destination share and use the verify button, it fails - with the error 0x80070056. Ok - so I set the path and username and password again, click Verify and all is good!

 

Back to the capture - fails again with the same error

 

Edit the TS and use the Verify button - fails again! Set the path and username and password, Verify works - save the TS and try to capture and the same error again

 

I'm going around in a loop here as the account has full access to the share to write the image - but every time I save the TS and then re-open it the permission fails so I'm not sure what's happening

 

Anyone else use a TS just to capture an image (rather than use the full Build & Capture TS that SCCM offers)?