One of our MVPs was having some trouble recently with POOM and traced the problem back to our device images. We didn't get the POOM type library into the ROM images in our 2003 release, unfortunately.
If you're doing POOM development and need the type library you can find it in the eVB runtime install for Pocket PC. When you install the eVB runtime it should install and register pimtlb.dll correctly.
[Author: Neil Enns]