Sleep isn't supposed to lose any application state, but I've certainly had many issues before with applications freaking out after waking up from sleep, on both a Mac and Windows machines. Sometimes it seems like more of an issue with the way the application handles sleep/network interruptions etc, but the end result is still the same.
There is another comment floating around on this thread about how expecting network state to be preserved after sleep is unreasonable; when the system wakes up most likely its open connections will be stale. Might as well close them gracefully at sleep time.
