Ive had the same problem when working on my robot. The issue is that the buffer (either that or the variable that contains the interpreted code) is retaining that value, you need to clear it out. I can't really see it in your code but, there may be a problem with interrupts, they must be allowed for the new IR codes to be recieved. Id also place a few serial prints in there to see if your program is running through the whole loop.
also if I remember correctly, irsend stops all other IR processes. If this is true, another irresume is required to continue reception. 