I found a couple of Connect articles on this that were closed with no real resolution. The one that really gets me is Buck Woodys' comments in this one:
Reading his response, the first paragraph states that only SSMS 2005 can connect to a SSIS 2005 service. Yet the second paragraph contradicts that, saying SSMS 2008 can connect and manage SSIS packages in both 2005 and 2008 databases (msdb). In order to do that, you need to connect to the service and that is the contradiction. I have a few 2005 servers with packages in msdb and can't use SSMS 2008
In any case, I can’t find a workaround so I need some help. We have converted our desktops (the DBAs) to 2008, so I had to reinstall the 2005 client tools to export packages so they could be edited.
"There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies."
"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair.