OK , so when you save a .xls file in 2010 from 2003 , explorer bugs you with : “filename.xls cannot be saved in the current format. To save your changes, click OK, then save it as the latest format.”

This dialogue box then breaks the iManage save as functionality which then brings up

 And you have to resave the document as a .xlsx or resave as a .xls which stops bugging you with message. This is no good for people with linked documents  . I have found no way to disable the first dialogue box/error

Solution for Explorer

1) Save the file to explorer , open the file with 2010 , click ok to the error message , then save it back as an xls ( overwrite )  , then you can open and save from explorer

Solution for iManage/Worksite

1) Save the file to explorer from your DMS file server, rename from docnumber.version to docnumber.xls , open the file with 2010 , click ok to the error message , then save it back as an xls ( overwrite ) , then you can open and save no drama’s from explorer

2) Rename file back to docunumber.version then copy this file back to the iManage file server and it enables the file to be opened saved from 2003 and 2010 no errors.

So 2010 must rewrite the file with new meta data!