A memory leak seems like something you'd want a fix for, and Microsoft would want to fix. This wouldn't be worth more than a couple of paragraphs in a news story, except that Microsoft has chosen to respond . . . oddly.
Given the company's penchant for throwing updates and fixes at us in Windows Update, you'd expect to see a fix listed in the next set of updates. But no, no automatic fix-and-forget. Apparently Microsoft has known about the problem for long enough to get a fix into Vista Service Pack 1, but didn't put a fix in there, either.
There is a fix. You just have to ask for it. There's an article in Microsoft's Help and Support Knowledge Base (go here) that describes the problem -- "This problem occurs because of a memory leak in the Windows OLE component. This memory leak is triggered by the way that Windows Explorer deals with the extended attributes of the files." The solution: "To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to request the hotfix, go here." It's a generic request form that requires the Knowledge Base article number, which is not easy to spot, so I'll give it to you: 942435.
Or you could just start rebooting Vista every once in a while. Just in case. But wait, wasn't Vista supposed to fix that?