Firstly I love your plugin - by far the best breadcrumb trail plugin for WP. I am, however, developing a site with multilingual functionality and for that I'm using WPML.
There's a minor issue with how the categories display in the breadcrumb when a language with the same translation is displayed though. That is when the same category name exists in two or more languages then WPML has to add a @es (language code) suffix to the category to create a unique name for WordPress. On their own breadcrumb trail plugin (which isn't that good as it doesn't have many options compared to yours) the suffix is filtered from the front end but on the NavXT plugin it remains in place.
I added a post to the WPML forum here http://wpml.org/forums/topic/it-es-etc-etc-in-categories/#post-64474 and they mentioned that it would be good if you could get in touch with them to help resolve the issue. Here's what they said…
" If you'd like us to work on this with the author of NavXT, please check if they're willing to spend some time with us. The changes on their side will be pretty trivial. They'll just need to change the function that displays taxonomy to the standard WordPress API call and everything will work great with WPML. If you contact them and they're interested, we'll help them make this change very quickly. We cannot take responsibility to their plugin, so we need their cooperation in doing this change."
"You can ask them to go here:
We'll create an account for the other plugin developer and work together to make things compatible."
Is there any chance you would be able to do this?
I realise this is a big ask but from the sounds of the WPML developers it wouldn't take too much to make things compatible and then your plugin would be really useful for those developing multilingual websites.
Thanks in advance for any help you can give on this issue.