I have a weird problem. When I use the mouse to rotate/drag the camera in build mode, it moves very slow. It is as if I have an old 90's mouse that needs cleaning The weird part is that I don't have the problem in live mode when doing the same using the mouse. I also don't have the problem when I use the keyboard to rotate the camera in build mode.

I tried searching this, but all I can find are problems related to general lag and slow responding.

Does anyone know what can cause this?

Not sure at all if this is relevant for you, but I get that same kind of "drag" on the mouse in build mode when the game has to load wallpapers, rabbitholes (oh so many rabbitholes) or even fences. The lag usually disappears if I switch to Buy or Live mode quickly but it will return. So, loading times of too much (possibly corrupt?) content, basically. Why this does not affect keyboard rotation is beyond me, though (and yes, same here).

Thanks for the help, but this doesn't explain why I don't have the issue when rotating the camera using keyboard. Or in live mode when using keyboard or mouse. As for memory, TS3 being 32bit, in my experience always uses close to max memory for 32bit. Just checked, was at 1,6Gb in build mode.
This was on an EA built (no CC) lot when in build mode (one of those ugly starter homes). No matter what tool I switch to. The moment I switch back to live mode or use keys, the weird slowness for mouse is gone. Everything else works smoothly. I also never have lag with buy mode. So I have trouble accepting it has to do with CC. Also, other things I do with the mouse in build mode are no problem. Just doing stuff while holding down a mouse button it seems. As if the game in build mode has some weird bug where it doesn't give the mouse input enough priority. If this can be caused by a mod, then a lot of people would experience the same, because I use the standard NRAAS stuff. Actually, now I read about about both your experience, maybe it does happen a lot and many just shrug their shoulders and think 'Oh well, it is the sims 3'It has a workaround after all by using keyboard.

The mods I Use are the basic NRAAS things (SP, MC, Overwatch, Register, Careers) and CAS CC. No buy mode CC or graphics related mods. Oh and this happened when I started to prepare a new game in Sunset Valley. I didn't even create a sim yet :/

I probably have to get used to rotating the camera using the keyboard, I do must things in build mode with keyboard already anyway.

I think you misunderstood me. When I try to rotate the camera using the mouse (holding middle mouse button), the camera rotation speed doesn't come even near to the speed when using the keyboard. So it definitely is not a performance issue about whatever is build around there, because keyboard speed is normal. Besides, I am talking about the starting homes in Sunset valley. No complicated structures there. For me it is also very consistent.

Summary : Dragging/rotation camera (only) in build mode moves as if I am dragging the camera through mud. In live it is normal. Stuttering I get in live are the normal expected stutters I sometimes get when it loads a neighbour lot because I hover over it a bit. Using keyboard to manipulate camera works normal in all modes.

Also I would expect that live mode is more taxing for your pc when rotating the camera. And yeah, the weird behaviour in build mode, makes me want to check batteries and clean my corded optical mouse :p

I am used to look up guides to troubleshoot performance in games. I hate any kind of noticable latency, so I always do my best to make games run as smooth as butter. Performance > Graphics for me. But TS3 is always an exception. It always feels kind of messy and it is as if I always find some new weird problem in that game and I never get the feeling I am in control of the situation. Almost makes me become superstitious, wondering if I should wear my lucky 'Today TS3 ran smoothly ' t-shirt :p

Anyway, thanks for your help trying to fix this. But I am just going to use keyboard from now on and have some fun

I have this same exact problem! Did you ever figure out how to fix it because I can't stand using the keyboard to rotate the camera.

omg i totally forgot about this thread haha. but anyways, i have the game running on a completely different setup since then and i still run in to this quite often, but on build mode only.