Further implementations of the latest RiO community and mental health software in London and the South have been put on hold until September.
The mounting delay means that up to five months will have passed since installations were stopped in April.
Local service provider BT and the London Programme for IT previously said they planned to resume implementations by May.
Installations were suspended after slow response times and performance issues were reported with the Spine-connected RiO 5.1 software.
In a statement to E-Health Insider, LPfIT said: “NHS trusts, the London Programme for IT and BT are planning to recommence deployments in September 2009.
"Establishing the source of the problem took longer than expected and we’re working with BT to ensure the recent upgrade, RiO version 5.1, continues to deliver a stable service.”
Version 5.1 is the first version of the RiO software to connect to the full NHS Spine infrastructure. RiO is installed in 31 trusts. Twelve RiO sites received version 5.1 before the freeze was put in place.
The upgrade introduced smartcard authentication for the first time, requiring staff to use the NHS smartcard to access the system.
Under the terms of its June £546m LSP contract extension, BT is also responsible for providing RiO to 25 community and mental health trusts in the South of England. These are also understood to be on hold.