Haha, I can´t remember any, there obviously some words having different meaning, but nothing outragoeus
for example
Vedro is in SVK (Bucket) in CZE (Heat) or Topit is in SVK (drown) in CZE (stoke the fire)
I know we have such problematic words mainly with other slavic countries
with Poland is the most funny word Šukať/Szukat in POL it means (searching) in SVK/CZE it means doing...well,, (Fucking) I remember once when I was young and camping with my dad, we had a family of tourists from in a tent next to us screaming the whole night, Szukaj ! Szukaj ! , I almost was pissing my pants how much I laughed that night, the next morning we learned that they were just looking for some lost watches
Also as I wrote it here somewhere a couple of weeks ago in you ask for cold drink "Hladna piča" but don´t say it in CZE/SVK because it means "you hungry cunt"