If you raise a case in your company's dedicated support group and report the issues there Jive will investigate and may decide to file bugs if you have reported unknown issues. Jive can also link the bug to the case so you can monitor its status. I don't think it's possible for customers to search against existing bugs.
Start by typing your known issue into the search field. Some bugs are documented with the appropriate way to fix the issue. If you cannot find a documented answer then log a support case.