Hey @Kostas,
I’m sorry to bear this news, but I do not know of any Translations plugin that we fully support 🙁
Our plugins are fully compatible with all default WordPress translation methods. Each “translation plugin” uses different non-standard methods for applying their plugin-specific multiple translations, and so we do not have 100% support for any of them.
In general, it seems like qTranslate has better coverage than WPML, though again this coverage is not 100% and I cannot confirm that it would solve your specific issue here. 🙁
I’m sorry @Kostas!
— George