I am using EE 1.6.1 and am also experiencing problems with TinyMCE / LG TinyMCE Custom Field Module.
Like ruraldreams, I get the “r has to properties” error in my JavaScript Console. I have many custom fields that are text areas which should be converted into TinyMCE, however only the first two convert. The others don’t. This happens on all browsers as well (the issue is not browser related).
Further, when outputting the content of TinyMCE fields, line breaks are being inserted when they shouldn’t be. Like the TinyMCE tutorial stated, I have set these text area fields to the format of “None” and NOT XHTML nor Line Breaks.
I guess TinyMCE wasn’t tested too well with 1.6.1. I hope this gets resolved soon.