Hi @jmruas,
Thanks for the link. Looking at your site, Waymark is conflicting with the OSMapper plugin you have installed, which also uses the Leaflet JavaScript library.
I have created a new development release of the plugin (currently v0.9.12-a1) which I believe fixes this issue.
You can download the development release here and requires manual installation. I also recommended a full backup of your WordPress install before activation, just to be on the safe side.
If this resolves the issue for you please do let me know, and I will ensure this fix is included in the next release.
Best regards,
Joe