unwanted call to db.pas

I am attempting to upgrade a D1 app to D5 and have encountered the following
problem.  When I attempt to compile each of several projects, the compiler
tells me it can't find the db.pas file and specifies the last search path in
the library path list as the location -- obviously having searched through
all paths.  I don't have the vcl source directory in there...I'm not seeing
why it needs that.

It's got the db.dcu file in the path, but it's not showing me the tooltip
filename location in the uses clause.

Am I missing something completely simple?

Thanks in advance for any advice,

Gary