Running old iRules after an upgrade

We updated to a newer version of 14 and noticed something which has me questioning my sanity. I have an iRule that acts like a DNS proxy to internal servers. I noticed this morning it was returning an old address (old as in one I changed 3 months ago). I verified on a system that the address being returned was the old one. I then went into the iRule and simply added a space and resaved it, then it started working correctly.

I have seen this behavior before where simply saving the iRule again seems to change what is running.

Are old versions of the iRules kept around somewhere and could possibly be pointed to until I do that save and the current one runs?

I realize this sounds bizarre but the only place that returned the old IP address was the iRule (no hosts file, etc) and as soon as I did that save, it started returning the new address.

Thanks, Tom