JJordon,
Here is the list of 5.1 versions and when they were released.
5.1 SP5 Mitel 5000 CP v5.1 (Release 43) 5.1.0.57 October, 2013
5.1 SP4 Mitel 5000 CP v5.1 (Release 32) 5.1.0.46 November, 2012
5.1 SP3 Mitel 5000 CP v5.1 (Release 25) 5.1.0.40 August, 2012
5.1 SP2 Mitel 5000 CP v5.1 (Release 21) 5.1.0.35 July, 2012
5.1 SP1 Mitel 5000 CP v5.1 (Release 19)
(Australia added Release) 5.1.0.35 June, 2012
5.1 Mitel 5000 CP v5.1 (Release 6) 5.1.0.20 December, 2011
So, basically you are at on of the earliest releases and need to make sure that you at least get them to the latest release of that version; which is on Mitel's main software download along with the release notes to let you know what is being fixed.
Thanks,
TE
P.S. don't forget to load the shellshock bug fix as well