I seem to have solved the problem by renaming the ReadyBoost pen drive from E: to U:

A change in drive letter shouldn't matter if it's just a reinstall back to the same drive as before. I haven't had any problems with that.
However, since the last stable version, an issue with an outdated USBmass file that has been somewhat improved (in recent betas). It caused some
problems syncing devices via USB. It may be related to your problem, not sure.

Check out mantis:
http://www.ventismedia.com/mantis/view.php?id=12383

I have the latest MM, running on Win7 64 bit Lenovo laptop. Recently re-installed Windows and MM.

There were some changes in drive letters after the fresh install, and I found that the Global Podcast Options for Download Podcasts To was set to a thumb drive (E:) running ReadyBoost. So MM threw a lot of errors regarding Not Enough Drive Space.

I fixed this (I thought) by setting the option to the correct (F:) drive, but MM still keeps trying to download to the E: (ReadyBoost) drive.

If I remove the ReadyBoost drive I can get it pointed to F:, but as soon as I try to use ReadyBoost again MM resumes trying to send podcasts there. Meanwhile, my F: drive designation in the options has not changed.

Any idea what might be going on?

MM seems stuck on sending podcast files to the wrong drive letter.

Maybe I should just dig into Windows and change the ReadyBoost drive to some other letter.