>>I seriously damaged a great relationship with a client over their
Pretty much same here - luckily I was able to jump ship to another cart early enough in the project to save things, but was a few sleepless nights migrating everything at the last minute.
@websta - thanx - am definitely interested in Cart 66 - for the project I bought this plugin for I ended up using Marketpress (Lite version for now) - loving the fact that it uses native custom post types and gives me complete control over pretty much everything out of the box. Cart 66 was a very close second for this currently project, but I just couldn't justify spending money again when things were in such a mad rush to get finished up.
Once things settle down a bit after this project I'm definitely looking at giving Cart 66 a try.
Main reason I'm posting stuff here at all is as a major warning for other potential victims of their shoddy business practices. buyer beware indeed.
I've run into this kind of thing over in the Joomla community, but this is the first time I've seen this kind of behavior personally anywhere near wordpress. Sad.