There seems always to be some serious confusion about how to install components in Delphi (packages are not loaded after restart or are not found when used by other packages, suddenly error messages are shown like "device does not function properly", strange compiler messages appear because of version mismatches etc.), so let me first give you a solution which I found after
many trials and errors. It solved most of my
package problems now for a long time.
The core of the solution is to compile
always every intermediate file into the same output folder and put this folder into the system's search path. This means, chose a path (I use C:\Temp\Out) and set it as
dcu, dcp and
bpl output folder. Set this path also as library default path in the
IDE options and remove the default $(Delphi)\
BPL path which often led to misleading version information (or use this path
exclusively as compile target). This way you will always find only one version of your bpls and the
IDE is able to use them, particularly if you have deep dependency nesting, as I do. You can still have several source folders but use only one output directory (of course, final project results like exe or
DLL can be compiled into their respective local folder, they are not shared and hence do not have this problem). Don't forget to take this output directory in the search path of the system (PATH variable in autoexec.bat on
Win9x/Me and My Computer/Properties/../Environment Variables on Windows NT/2K/XP).