PC Gen: 3Com XNS and Mail May Cause Computer to Hang

• Microsoft Mail for PC Networks, versions 3.0, 3.0b, and 3.2

SYMPTOMS

With version 3.0, 3.0b, or 3.2 of Microsoft Mail for PC Networks, the computer may stop responding (hang) when it is left unattended. This problem can occur if you are using a slower computer (8088/80286) with a slower 3Com network card (such as an 8-bit 3Com 3C503 or 3C505), over a 3Com XNS-based network.

CAUSE

This problem is caused by a known XNS timer interrupt chaining problem. The computer will hang if you have numerous timing related events running simultaneously (for example, the 3C503 driver, the LAN Manager redirector, Mail polling, Word autosaving, and 3Com XNS).

RESOLUTION

Possible solutions are to use a configuration that minimizes the amount of time-related events. Examples include:

• Making the polling of the client/External less frequent
• Using a 16-bit network card (3C507)
• Making sure the interrupt setting of the network card is set to the lowest value possible (for example, 2 or 3, rather than 11 or 12; the lower the IRQ value, the higher the priority to your card).

STATUS

3Com has confirmed this to be a problem in 3Com XNS. 3Com is researching this problem; Microsoft will post new information here in the Microsoft Knowledge Base as it becomes available.

3Com XNS is manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.