Use the InDesign CS4 Preflight panel to create a Preflight profile that checks for resolutions within your needed range. Observe for errors that indicate an image's effective resolution is out of that range.
Note: The Preflight feature only reports on the effective resolution of an image. For example, for an image with 72 ppi, scaled down to 25% of its original size, Preflight reports its effective resolution of 288 ppi (4 x 72).
For other file formats, InDesign reads the image resolution while importing for the firs time, or when updating an existing link. It then caches the information in the document for quick reference later. The Photoshop EPS import function does not have methods for caching the resolution information.
Currently this issue is a designed limitation for InDesign.
Resolution information may also be missing for PDF files that contain multiple images with different resolutions, or that contain no images.