I will be performing a server upgrade within the hour. Since I do not expect it to be down long, I didn't bother to wait out a day so everyone will know it's coming. This is out of necessity, as at times people are seeing "waiting on carls-sims-3-guide.com", which is a result of the server being out of memory and not able to serve as many people simultaneously as is needed. After the upgrade, we'll have twice the memory as before so this should happen much less frequently. This was planned to happen with the launch of TS4, but traffic on the server is high enough that it is already running out of memory and unable to serve people quickly. I didn't really want to do it on a weekend in the middle of the day, but the problem will only get worse as we get closer to July, when traffic peaks.
If this happens after this upgrade, it is a result of slow connections between your location and the server. Prior to this, it was likely the server.