"I have some problems with that program."
Translation:Mi havas kelkajn problemojn pri tiu programo.
The difference between 'iom' and 'kelkaj' is that 'iom', as part of the correlatives, is quite literally 'some', or more precisely, 'some quantity'. 'Kelkaj' means 'a few' or 'several' (think quelque if you know French). Thus, both fit the sentence appropriately. I might personally lean towards 'kelkaj' as sounding natural given the context.