App Server, Another user has changed the definition of table

Hi,

I have a Application server running agaings a NAV database on a SQL Server. The Application server reads from a LinkedObject (table) located on a remote server. Occassionaly during night allways right after midnight a error message is trown in our Error handler it states:

Another user has changed the definition of the vwTopOrder table after the activity was started.
Start again.

We have 8 application server doing the same thing in 8 different companies. This error do not occure in all of them simultaiously. Some night its only 2 of them some 4 and so on.

Obviously I do not go up at night poking around in these obejcts causing this,or perhaps I am sleep walking I dunno ....

Please give some information on how this can happen.