The link you provided use 'hicup' in different terms... It is all in the context of what is being discussed. If someone mentions a hicup with regards to a power supply, it would imply voltage spikes as IrishNinjaX stated.....
In the 1st example, they are talking about overclocking memory. When they say hicup, they meant the system ran stable up to that point.....
The 2nd link you posted, is again about memory.... Running games without a 'hicup' would mean they weren't choppy or full of artifacts.
The 3rd link is again talking about games... but it is refering to the video card.
4th link is again about memory.....