Please don't take what I am about to say the wrong way. Anyone who takes the time to offer help here is truly appreciated. However....
Advising the OP to change memory blocks without explaining why could confuse the issue as he could take your advice without realising the need to re-enter all his speed dials. Also for all we know, the block you are suggesting using could already be in use as personal speed dials and this could lead to the OP wiping out up to 1000 personal speed dials, which he/she would have to then rectify. I understand your reasoning but please bear in mind that the people asking for help may not truly understand what they are doing with our guidance and so we need to tread gently.
That said having not seen you post here before I need to say welcome and please don't be a stranger.
OP: I should also ask if you are aware of the need to backup your changes to the flash rom? If you want to test what you have done before committing to it permenantly, you can wait before saving it to flash and if you aren't happy, simply reset the system to get back to the pre-change state!
A word of warning though, I was recently caught out by the fact that a previous tech hadn't saved his changes to flash. I reset the system and lost changes I hadn't made! Save first, then save last!
If you aren't sure how to do this simply log on then log off and you will be prompted to save as you log off. However a backup to disk before making changes is even better but bear in mind that the backup is from the flash not from the working config!