I'd say its driver related, usually the sound card drivers. Either that or you've got too many devices sharing the same IRQ Number.
Taken from Microsoft.com...
http://www.microsoft.com/resources/...Windows/XP/all/reskit/en-us/prmd_stp_ottj.asp
Stop 0x000000D1 or DRIVER_IRQL_NOT_LESS_OR_EQUAL
The Stop 0xD1 message indicates that the system attempted to access pageable memory using a kernel process IRQL that was too high. Drivers that have used improper addresses typically cause this error.
Interpreting the Message
This Stop message has four parameters:
1. Memory referenced.
2. IRQL at time of reference.
3. Type of access (0x00000000 = read operation, 0x00000001 = write operation).
4. Address that referenced memory.
Resolving the Problem
For additional troubleshooting suggestions that apply to all Stop errors, see "Stop Message Checklist" later in this appendix.
* Stop 0xD1 messages can occur after installing faulty drivers or system services. If a driver is listed by name, disable, remove, or roll back that driver to confirm that this resolves the error. If so, contact the manufacturer about a possible update. Using updated software is especially important for backup programs, multimedia applications, antivirus scanners, DVD playback, and CD mastering tools.