It seems like every time Microsoft release a new service pack they introduce a DLL load address regression with it. For a little background on DLL load addresses and the problems they can cause for applications such as IDS refer to an earlier blog entry.

This time the culprit is the home networking configuration manager DLL hnetcfg.dll. In IDS installations with large shared memory configurations on Windows Server 2003 SP2 oncheck can fail with an error like this:

shmat: [22]: operating system error
MapViewOfFileEx: w32ec=487 at nt_shm.c:663
Unable to attach to shared memory.
Invalid argument

The default load address of hnetcfg.dll changed from 0x7F010000 in Windows Server 2003 SP1 (with KB913409 hotfix) back to an address space fragmenting 0x5F270000 in SP2.

To resolve the new problem, ask Microsoft for a fix of KB 948656.

ps. Thanks to Tim Steele in Australian Advanced Support for keeping track of these defects and chasing Microsoft.