The last thing I do before my final build is to de-activate all my connections - I've had that same problem many times.
I handle the runtime aspect in one of three ways:
1) I have the connection string in an .ini file
2) I have the connection string in the registry
3) I pass part or all of the connection string as a command line parameter.
I have my tables, datasets, connections, etc. in a datamodule. In the .OnCreate event of the datamodule is where I get the connection string and assign it.
Good luck,
Djangman