Are you putting them in the control flow item "execute dts 2000 package task" ?
If you're not - open up Visual Studio, Click Project - > new - > business intelligence -> Integration services project.
create a package (Right click on the project name and say "new package" or just use the one that they give you so you can see how it works), drag a "Execute dts 2000 package" task over to the control flow. Double click on it. Give it credentials and you should be golden.
(Or you could rewrite them in 2005/2008. Which would allow you more functionality.Just a time investment).
Note - you will need to have SSIS installed (comes with the installation of SQL Server).
