WordPress truncating shorctodes

I’m having a really weird problem – WordPress keep truncating the wp-filebase shortcode every time I make a change to the page or post. What happens is that every time I change something (unrelated to the wp-filebase shortcode itself), the shortcode gets truncated like this:

THIS
[gn_tab title=”something”][wpfilebase tag=list id=’3,4′ tpl=’table_list’ sort='<file_id’][/gn_tab]

BECOMES THIS
[gn_tab title=”something”][wpfilebase tag=list id=’3,4′ tpl=’table_list’ sort=’

gn_tab – shortcode for tabs (Shortcodes Ultimate plugin)
table_list – my template for displaying list of files

Now I do have TinyMCE installed, with loads of plugin for it, so maybe some of them are causing this, I’ll have to test this, but I’d love to know if somebody had similar problems.

I’ve installed Auto formatting plugin to stop auto formatting of the text, but still the same thing happens.

Can anyone help? What would be the failsafe option – TinyMCE, but with all of it’s plugins diabled or what?

Any idea at all is welcome.