Within an Intel SCS 3.x environment, if you're experiencing repeated w3wp or amtconfserver service failures - the following may be of interest.
There are newer versions of Intel SCS available at http://software.intel.com/en-us/articles/download-the-latest-version-of-intel-amt-setup-and-configuration-service-scs/ - the latest production version as of Jan 2009 is 5.2, and beta versions for 5.3 and 6.0 are coming soon. Each successive version provides new features, fixes, etc.
But - if you're using Intel SCS in combination with a management console - it's best to stay in compliance with the latest certified version of that console.
For example - Altiris 6.x environments use Intel SCS 3.x. There is an option to use Intel SCS in a standalone mode - and some customers have taken a unique customized approach of using SCS 5.x in an Altiris 6.x environment.... but, the preference is to stay in compliance with the released version.
Another approach is to isolate the environment in which Intel SCS is running - thus preventing a fault by Intel SCS from affecting other w3wp processes. One approach in doing this is stated at the following link - http://www.symantec.com/connect/articles/w3wp-and-amtconfserver-processes-keep-failing
If other insights\ideas from the community - please state.