Only after installing this plugin did I read somewhere that it's not single site compatible.
Look... I'm getting very frustrated here. I'm finding that nearly every plugin of yours that I install does not work on a single site. Now, I realise that your name is WPMU - which suggests a focus on MU - but it isn't a 'given' that plugins designed with MU in mind won't be single-site compatible.
I am beginning to feel as if your marketing materials are misleading. That you are encouraging people (like myself) to sign up to a membership package, only to discover after-the-fact that half the things that they are interested in won't work as advertised.
I feel this way because your plugin descriptions lack critical information.
I would sincerely suggest that you create a "not compatible with" tag alongside your "compatible" tag in the plugin intro & usage pages. That way, people can clearly see what isn't going to work before they sign up for a membership.
Google Custom Search Plugin "not compatible with: any other search plugin"
Global Site Search Plugin: "not compatible with buddy press activity or Group Forums postings; compatible with standard wp posts only."
Avatars Plugin "not compatible with single site installations"...
This is just the beginning of my list... I am starting to get annoyed because nearly every plugin of yours I want to use has some huge, glaring omission from your marketing materials so that I find this out only after-the-fact.
Better still, why don't you have a checklist for EACH and EVERY plugin that says exactly what it IS and ISN'T compatible with in regards to:
Single Site vs Multi-Site
And - while I'm on the topic - it's not good enough to say 'compatible' with Buddypress when it doesn't actually work with Buddypress. In other words, you often use this 'compatible' term to mean that it won't break when in the presence of Buddypress. That's very difficult from 'works with' or 'integrates with' Buddypress.
Sorry for the rant but I really think that your plugin descriptions are seriously lacking in useful technical details. I have spent days installing plugins of yours only to discover that they don't work in my environment. I say 'days' because your documentation is lacking and I often have to search your support forums until I find some unfortunate soul like myself who has encountered the same trouble.