not compatable with https://ww.wp.xz.cn/plugins/secondary-title/

Sir,
I use https://ww.wp.xz.cn/plugins/secondary-title/ plugin on my blog (http://vigyaan.org). When I installed your plugin – all post title were duplicated. I noticed that it happen only if I give secondary title using ‘Secondary title’ plugin. If secondary title is not there – it does not duplicate. I tried several option – nothing helped, so had to uninstall at the moment.