We've seen a number of reports of issues with Yahoo hosting ranging across many of our products. The error messages we've seen with regards to Builder running on Yahoo hosting never seem to make any sense, which could indicate an overly-complex or very outdated server setup. In each of these cases, the user reporting the issue said that the problem went away as soon as they moved over to different hosting.
In general, we've found many customers that can't get good results from Yahoo hosting. For example:
first off ill just admit that i hate yahoo small biz hosting for a multitude of reasons...even tried to get this client to NOT use them - but we are way past that.
I have just posted two particular problems--with image modules and rotating images plugin--elsewhere on these forums and it suddenly occured to me that the problem might be the Yahoo host. I started putting together a Builder/Noise site in a sandbox on my BlueHost account and everything worked fine. But my client has been on Yahoo for years and doesn't want to move. So I tried to rebuild the site on Yahoo and nothing works.
I have had major issues using Yahoo. I had to set up a site for a client who was not going to switch and wish I had charged them more for all the issues I encountered. I would avoid Yahoo and GoDaddy hosting at all costs. Just my two cents.
Beyond just our products, I've also seen reports of people having issues setting up caching plugins or using the permalinks feature of WordPress on Yahoo hosting.