Currently, JIRA issues which are "fixed internally" get a status of "resolved", which prevents any further voting, regardless of whether the fix has actually been applied. This is a problem for two main reasons as I see it.
1. The issue has not actually been resolved, it is still active until a fix has been applied to a release client. The classification of "resolved" is therefore not only terminologically incorrect but could also confuse both readers and, dare I say it, potential fixers. Residents may start bug reports as they see in their client that the issue is still present, and it may be sidelined for fixing within LL. No issue should be called "resolved" until it actually has been in practice.
2. Marking an issue as "resolved", as mentioned, prevents further voting. However, this provides incomplete information. If the issue is still very much live on the grid and is still causing problems - say, it has been recently used in a widespread grid attack, and only recently people have become aware of it - votes for its importance should be recorded and used to determine priorities, as with an issue that is not "fixed internally". To users it makes no difference that a potential fix exists in theory but has not been applied.
I would propose therefore that "fixed internally" not close the issue and merely be another status prior to the actual resolution, which would be incorporation of the fix into a release client.