I have several one-singled families, that always stands at the mailbox/gate as if they just moved in, although they lived there all their lifes, and all furniture and everything is still inside, as it was the last time I played.
I have tried to get another sim to move in so they can do something together, like watching TV.
As they do, I save the game, get to the Neighbourhood and load the "family" again, and both sims are there, but the one that just moved in at watched TV, is sitting in the thin air (tried to buy a new sofa - didn´t help) in the middle of the livingroom, and the "original" houseowner is standing by the gate, as if she was the one that just moved in (yellow levels on her needs etc.)
She is not frozen, can do whatever I tell her to, and time is running as it should.
I can also take her downtown and back again, and everything is normal, but as soon as I have saved her, jumped out to the Neighbourhood and then load her again, she is still standing by the mailbox, whith her needs on yellow, but the clock has ticed as it should, for ex. if I played her 10 sims-minutes and then left her, the 10 minutes are gone as I reload her, so that is not a problem.

I also have tried to move her out completely, selling the furniture and everything, also placed the lot somewhere else in the neigbourhood to really start all over, and when she moved in and sat in her new sofa or by the computer, I saved and went to neigbourhood.
As I reload her, the newly sim that moved in is still doing whatever she was doing, like a normal sim, but the real houseowner is standing by the mailbox, as before...

I dont know why this has happened, and I dont know how to fix it, so please help me,

Thank you, Kindly regards / Zorna

Have you done the Game Help:Game Problem^wiki FAQ? If not, please do. If it didn't help, please tell us exactly what you tried to fix the problem, and the results of all of your tests.

I searched it through, and all I could find as a similar problem, is the one stucking in the pool, but I started with copying Neighbourhood to the desktop, removed Lot Catalog, Downloads and Saved Sims.
I used your step-by-step and I really thought the problem would disappear after I removed them, but she was still standing yellow at the mailbox, so I moved out the temperary (?) sims that just moved in, saved and put the houseowner to the stove, cooking.
I saved and went to the Neigbourhood (because I should recreate the situation, I just had to load her, letting her do something, save and go to the neigbourhood and reload her), but there she was - at the gate...

So I made the backup of all files, loading the game with new and fresch folders (exept for the neighbourhood, because I wouldnt have the same families in the new one - was it wrong?

The same situation accured (? sorry for my bad english) and I thought that since I always lock the gates and doors for "other than the household), I may have by misstake letting the temperary sim lock the door, and when I let her move out without locking it up, it could be the reason.
So I removed all fences and the gate, saved and reloaded.
Yes, the fence were gone, but she was still standing by the mailbox...
This is so wierd, because I have almost 20 other families in the same neighbourhood, and apart from her, there are only three other families that has this problem, and as long as I can play with them and not stucked or frozen, I guess it is ok, but its enoying (?)...

So I got to the part where I shall download the patches, but since i am not interesting in computers, I search for an explaination for what they do, but I dont understand which one to download (yes I searched for that, and found out that I have to download everyone, and I do have enough space in the computer) but some of them are for dvd:s..?

I really appriciate your answer and help, since I am totally blank when it comes to computers, so please tell me exactly step by step ( that is really good) what I should do...

Have a nice day, kindly regards / Zorna

Oh, you definitely need the patches. What they do - what any computer program does - is fix bugs that got into the published version. This isn't likely to fix this specific problem, because it's unusual and patches are generally made to deal with bugs that are brought to the attention of the staff by repeated complaints - but it will fix some other bugs you haven't noticed yet.

Do not play the Ottomas or Critturs families in any of your existing neighborhoods! The patch for the Seasons expansion fixes a very bad bug that will corrupt these families if played and allowed to have the babies with which Samantha Ottomas and the dog are pregnant; but it only works on Ottomas and Critturs families that are created with the patch in place. Your existing ones are hopelessly broken, but won't cause problems if left in the bin, or if the pregnancies are terminated with a hack.

Sorry not to be helpful on the other problem. It sounds like the sort of thing that's caused by bad CC, but your removal of the entire Downloads and Saved Sims folders should rule that out.

You have 3 types of patches CD, DVD, "Digital Download (DD)" and you only need to download for what you have.