Notebook and laptop computers based on Intel's new mobile and wireless Centrino chip architecture  can experience a "blue screen" crash in Windows XP when running widely distributed virtual private network security software from Nortel Networks, according to Mike Schexnaydre, a Nortel software engineer.

Schexnaydre said Nortel has determined that the blue-screen crash, in which the operating system stops functioning, stems from problems with the Network Driver Interface Specification within Intel's PROSet software.

The Centrino architecture, widely adopted by notebook and laptop PC manufacturers after its release in March, includes a Pentium M mobile processor and an 855 chip set, which helps manage power consumption, graphics, and USB ports.

Schexnaydre said that the conflict between Centrino and Nortel's Contivity VPN client stems from an adapter-switching feature in PROSet that allows users to automatically change from a wired to a wireless connection.

Nortel has developed a workaround to the problem that requires IT departments to uninstall the PROSet drivers, according to a technical bulletin released by the company May 14. The bulletin said this workaround will allow the Contivity client to operate with Centrino, but at the expense of the functionality of the Intel PROSet software, which controls features such as wireless LAN setup profiles, roaming, and a connection wizard.

Schexnaydre said the operating system freeze appears to occur only with Centrino-based models that use the 855GM version of the on-board graphics memory hub and power management controller. Centrino-based computers with the 855PM chip set do not appear to be affected.

"It would have been better" if Intel had built Contivity support into Centrino from the start, since the company has already shipped about 50 million Contivity VPN clients since 1997, according to Pat Cooper, a Nortel spokesperson

Intel spokesperson Daniel Francisco said the company "is looking into the problem" identified by Nortel, but he declined to provide any details. According to Intel's Web site, the problem extends to all VPN clients, something the company was aware of before it launched Centrino on March 12.