I can't think of an example, the following doesn't make sense, I think(?),
Куда ты пошёл, когда ты читаешь газеты?
but illustrates my question. Are there times when context dictates mixing verbal aspects in a sentence?
PS. For example. If I wanted to say that I start reading the paper, but not finish my action, after going to the office, would it be;
Я читал газеты, когда я пошёл в офис.
PPS. A related question is.... Is mixing tense in English analogous to mixing aspect in Russian?