Do some people have big problems at work due to a learning disorder?

Yes: Many individuals with learning disorder can function well. Others struggle with tasks. It is important to consider talking with your h/r department about possible accomodations the workplace can make to help you.

Work and LD: Yes. Depending upon the disability, one might choose a career in which reading was not required and more of a hand's on approach was required. Similar occurences might exist with math, writing, spelling, etc.