@noppid:
Unfortunately, we completed a fix but it was not uploaded to the site in a timely fashion. The bug in the showpost URLs has been corrected. FYI This issue results in having a small number of showpost links repeated multiple times, which is not a big problem and is similar to having "showpost" pages disabled.
Note: The code is now updated here with the bug fix.
We are at production level. However, bugs are a fact of life in the software development lifecycle. As in the past, we will continue to do our best to provide fast upgrades whenever an issue (large or small) is identified.
Thank-you for being the first to alert us to this issue.
As for Yahoo sitemaps, we have not found any documentation indicating that the URLs need to be URL encoded. However, Yahoo just updated its
sitemap format. They accept either RSS or single URL submissions. So, we are now working on upgrading the plugin.