We just released Foxmarks 2.0.41 to the Mozilla Add-ons site (AMO). This version is essentially the same as 2.0.39 (the version that was up on AMO for several hours last week), but with two additional minor bug-fixes rolled in. We recommend that everyone upgrade to at least version 2.0.39.
As always, you're welcome to post your experiences here. If you are having a problem and would like a response, please write to customer support instead; we can't respond to specific customer issues here on the blog.