This is a duplicate report and/or the developers are already aware of this bug/problem.
Please check the feedback tracker to see if an issue exists before creating a new one and instead vote the original one up so the developers can see it's a common problem. (Most of the most popular will be up top if ordered by Priority).
You can also use the 'Filter' textbox to search through existing reports using a keyword if it's not close to the top.
A list of important bug/issues that the developers are already aware of can also be found on the DayZ Forums: