I've just spent the last hour and a half testing and re-testing (on multiple sites all running WP 3.0.4 and CFT 1.8.1) and can confirm a serious bug with the save button. I'd love for someone else to test it and see if they can replicate it.
I've got a pretty large template I'm working with (below). I see the previous post in regards to this has been marked as resolved, but I'm pretty sure it hasn't been resolved (or this is a new bug). I've tried (as I suggested in that thread) removing all spacing in custom field names but this has made no difference to the issue.
When I put data into the custom fields and hit Publish or Update, everything is fine. However, in an existing record if I use the SAVE button in the Custom Field Template edit box and then don't hit update, it not only doesn't save the data, it completely wipes most of the custom field data.
In the meantime I've switched off the save button. I'd love someone to prove me wrong - or to point out any errors in my template.
FYI: I'm using the Custom Post Type UI plugin v0.62 with about 6 different custom post types, however this particular template is being used on a standard page. I've tested this on two very different hosts too (both *nix based) - one of which is via our Hostgator reseller account - and had the same result.