Hi j n
There are no changes that can be made to the BEx Query that would cause AOLAP to change its layout or any customized work that was done by a user. Instead there will be warning messages. For example if a member is removed from the query which was part of a user defined calculation... or if a hierarchy was replaced by a different hierarchy in the query... these kinds of changes will cause AOLAP to issue warnings because it is not able to "redraw" the customized layout that it was last saved with. It will never revert to a default layout... worst case is that the workspace cannot be opened and whatever change was made to the query would have to be reverted.
Other query changes will not impact existing AOLAP workspaces, eg changing the format of numbers, conditional formatting... these can be done in AOLAP itself so these query changes would only impact new AOLAP workspaces and not existing ones.
It would be useful if you can identify any pattern to these reports about the workspaces getting reset. It would also be useful to confirm if the AOLAP workspace really has "reset" to the default layout defined in the query designer (ie if you create a new AOLAP workspace against the query is it really the same as the "reset" workspace?)
Of course, it is certainly possible that you have identified an issue that we have not seen before... but the folks I spoke to here had the same opinion that they could not understand how AOLAP could "reset" itself.
Let us know if you discover any common denominators to the reports.
Regards