Lossy channel systems (LCS's) are systems of finite state processes that communicate via unreliable unbounded fifo channels. We introduce NPLCS's, a variant of LCS's where message losses have a probabilistic behavior while the component processes behave nondeterministically, and study the decidability of qualitative verification problems for omega-regular linear-time properties. We show that – in contrast to finite-state Markov decision processes – the satisfaction relation for lineartime formulas depends on the type of schedulers that resolve the nondeterminism. While the qualitative model checking problems for the full class of history-dependent schedulers is undecidable, the same questions for finitememory schedulers can be solved algorithmically. Additionally, some special kinds of reachability, or recurrent reachability, qualitative properties yield decidable verification problems for the full class of schedulers, which – for this restricted class of problems – are as powerful as finite-memory schedulers, or even a subclass of them.