From
FGW▸ website
Line problem between Newport South Wales and Bristol Parkway.
Train services are being disrupted due to safety checks being made between Newport South Wales and Bristol Parkway.Engineers are working as fast as possible to restore services to normal. Short notice alterations and delays of up to 60 minutes can be expected.
Last Updated: 03/06/2011 09:25
Line problem between Newport South Wales and Bristol Temple Meads.
Train services are being disrupted due to safety checks being made between Newport South Wales and Bristol Temple Meads.Engineers are working as fast as possible to restore services to normal. Short notice alterations and delays of up to 60 minutes can be expected.
Last Updated: 03/06/2011 09:25
That'll be the Severn Tunnel then.

Already trains going via Gloucester. Havent been that way for ages.