ArcMap ArcIMS version 9.2 sites may experience slow rendering and loss of performance compared to previous versions due to several known issues.
The following are known issues identified in the ArcMap version 9.2 release:
1. Raster data in ArcMap Image Service may be slower in ArcMap version 9.2 versus ArcMap version 9.1 due to changes to the Raster Engine in ArcObjects. This issue is not specific to ArcIMS. The same slowness in rendering occurs when drawing the layers in ArcMap/ArcCatalog.
2. MXDs become corrupt or perform slowly when saving in ArcMap version 9.1. MXDs containing rasters with the unique values renderer use ArcMap version 9.2 and open again in ArcMap version 9.1.
3. A PDF generates slowly in ArcMap version 9.2 due to a bug fix that honors the Page Size setting. This setting was ignored in ArcMap version 9.1.
Workaround for Cause 1: Add additional spatial servers to power up the ArcMap virtual server.
<a href='http://support.esri.com/en/knowledgebase/techarticles/detail/22950' target='_blank'>How To: Add additional Spatial Servers</a>
Workaround for Cause 2: Resave the MXD in ArcMap version 9.2 or create a new MXD in ArcMap version 9.2.
Workaround for Cause 3: Alter the ENVELOPE of the extent to resolve this issue.
<a href='http://support.esri.com/en/knowledgebase/techarticles/detail/22713' target='_blank'>How To: Use the ENVELOPE tag in a GET_LAYOUT request</a>