When a search yields more sources for an existing download, resume that download. It used to work like this, but apparently it doesn't work like that anymore. Please restore the lost functionality.
Another interesting thing: if you select the search result in the top pane and click download, the download is not resumed. If you first remove the download from the lower pane using the (/) icon and then select the search result in the top pane and click download, it /does/ resume from where it left off. This strange behaviour suggests that the new behaviour is caused by a bug.