Google Maps and Yandex Maps doesn’t work correctly

These errors come from CSS rules from your WordPress theme that are also applied to elements on the map. For example, on your page, I was able to fix the popup by disabling the #content table and #content tr th rules which add extra margins. In a test setup I even got gray gaps between the tiles because of .entry-content img { max-width: 97.5% } in Twenty Eleven.

Map with gaps between the tiles

Probably the easiest fix would be to embed the map in an iframe so that the main CSS rules are not applied there (I don’t know whether you can do that with the API?). If that is not acceptable for your situation, you could append extra rules that undo the WordPress rules for maps (e.g. .entry-content .map-canvas img {max-width: none}), or ask the map providers to add more explicit rules (with !important) to the style sheets they provide.