I upgraded my MiKTeX installation to version 2.6 because I want to use pdfLaTeX 1.4 for microtyping. But it turns out that upgrading to MiKTeX 2.6 breaks the current release of Ipe:
Ipe cannot currently cope with the PDF output generated by the new version 1.40 of Pdflatex. This version is included in MikTeX 2.6 and in TexLive 2007. Therefore, Ipe does not currently work with MikTeX 2.6 or TexLive 2007. This will be fixed in Ipe 7.0.0, but since I’m changing many other things at the same time, do not expect this version before September 2007.
Thankfully, I also have an older laptop and with Subversion, it is not difficult to work on both simultaneously.