Can't start from Dock

I have been using 1.8 for the past several days.  Today I am unable to start DT from its icon on the dock.  Likewise, doubleclicking the icon in the application folder does not work.  I downloaded another dmg from this site and I can open the program from the mounted file initilly by double clicking.  Again, the dock icon and the icon in the application folder will not open by doiuble clicking but will oepn with "command-O"(open).  any ideas about the problem and cure.  Running 10.2.8 on an ibook.

Did you try dragging the current icon out of the dock and then dragging a new one in from the newly downloaded app?

Yes, tried that.  Like I originally posted, yhe program itself and the ico only work with command open, not by double clicking.  So far I have not found any other programs with the same proble including DAgent.

This kind of issue is usually one of "optimizing." You can run a re-prebind, even force one, depending upon which utility you use - Cocktail and TinkerTool System are both trustworthy maintenance appa.

Problem solved!!! OS corrupted, I was using 10.2.8 and had to run Norton Utilities twice in order to clean it up enough to instal 10.3.  So far the only remaining abnormality is that my Quicken files show that I made twice as much money last year than I actually did.  Fortunately, the permannet files are on another computer, and these files were for a backup to take on my laptop for work while  on vacation.
Thanbks for all your help