Intel has discovered a flaw in its recently launched chipsets that can stop a system starting up normally, and is planning a partial recall.

The 915 G/P and 925X chipsets, formerly known as Grantsdale and Alderwood, have a flaw in the I/O controller, said an Intel spokesman.

A chipset connects a processor to the rest of the computer, and Intel's newest chipsets incorporate a number of features that are designed to improve performance, including the PCI Express interconnect technology and support for DDR2 memory.

The spokesman explained the problem in simple terms. Chips are built in layers, with circuits added on top of other circuits. During the manufacturing process, a thin insulating film is applied to each layer before the next layer is built so signals do not leak between levels. At certain points on the chip, that insulating film is removed to allow the layers to communicate with one another. However, the insulating film on some of Intel's new chipsets was not completely removed from one particular area, he said.

The film is partially blocking one of the connection points and is not allowing signals to cleanly travel between levels, High said. This can cause the system to hang or fail during the startup process.

The problem only affected a certain proportion of Intel's chipset shipments because it was a manufacturing error and not a design flaw. Intel is not disclosing what percentage of its shipments were affected however. The bad parts were shipped to system vendors prior to the official launch and the company believes that very few chipsets actually reached end users.

Intel has identified the particular chipsets containing the flaw and is working with PC vendors and resellers to remove them from circulation, the company said.

Customers who want to buy PCs from HP or Dell with Intel's new chipsets will have to wait for several days as a result of the recall. HP's m1000 series Media Center PC went on sale on the company's website last week but will now not be available until at least July 6. Dell's Dimension 8400 won't ship until at least 20 July.

Intel is not the only chip company to report processor bugs this month. AMD also reported a bug in its Opteron server processor that could cause a server to fail. However, AMD's bug was caused by testers in AMD's lab running synthetic software instructions that only occur in very rare cases, an AMD spokesman said. The company is planning to work with server vendors and BIOS companies to distribute a work-around.