Did you have this problem from the onset of pacer therapy? It would seem more likely to be a lead problem than a generator problem. How long did you have it before you changed generator? If the electrical impulse is too close to the phrenic nerve, it will stimulate the diaphragm and cause the hiccoughs. The can be painful, annoying, or even interfere with breathing in worst case scenarios. Getting leads replaced is a bit more of a process than a generator change. Talk to either your md or your pacer company- medtronic (i.e.). Good luck, let us know.
I've heard that a certain placement of the pacer leads can lead to diaphragm spasms. Pretty annoying I'm sure. It would help to hear from others that have experienced this and how the doctors resolved the issue.
We'll have to wait a pacemaker expert/technician for the answer, but (not knowing what a generator is, a sub-part of the embedded pacemaker device?) it seems to me you should ask this question of whoever installed the new generator.
For those of us learning from reading these posts, you may want to explain "hiccoughing" - did you mean "hiccuping"? Either way, I don't know what it may mean, other pacemaker patients. My response should not deter their inputs.