AutoCAD LT :: Proxy Information Error When Loading Some Documents?

We just moved the Autocad LT installation for one of our users to a new computer and now when opening certain documents, we get the below error. The error didn't originally occur on the old machine, but after re-installing it on that machine, we get it there too. Is there a way to clear the error or find out which plugin we are missing? We have tried installing the plugins on the autodesk website, but weren't able to fix the error.

System information:

Autocad LT 2011

New machine OS: Windows 7 (64 bit)

Old machine OS: Windows XP (32-bit)

Error message:

Proxy Information

The drawing you have opened or referenced contains custom object created by an unavailable ObjcectARX application. You do not need the original application to display proxy representations of objects that were saved in the drawing. However, many manufacturers, including Autodesk, provide object enablers that also allow you to edit these custom objects.

Visit the AutoCad LT Object Enabler Assistant web page to locate Autodesk object enablers or contact the software publisher about object enablers for other applications.

Note: If your computer has internet access, verify that Check Web for Live Enablers is selected in the Options dialog box on the System tab to have AutoCAD LT automatically search for the Live Enabler website for the appropriate object enabler.

Missing Application: CAPxCAPDesignerDBX
Total number of Proxies: 230
Number of objects (no graphics): 230
Number of entities with no graphics: 0
Number of entities with bounding box graphics:0
Number of entities with real graphics metafile:0