It seems that profiles and such save in the default C: drive no matter what I do, and I'd really rather have it save in a dedicated folder instead. I'm running Vista 32-bit if that makes any difference.

Click the advanced button in the save window. Then choose the path you wish to save to. :D

Clicking "advanced" crashes the game. :/
That said, doesn't that just change where puzzles are saved, or does it change where profiles are stored as well?

I had a similar problem when I tried the game in Windows 7, I sent a support ticket in, so I'll probably get a response monday or tuesday. And I think it only puts your saves there, sorry. Not many games let you choose where to save profiles, even today.

Tried running the game in Administrator mode?

I have to, running it normally doesn't let it save at all.
Gamerkought, it's nice to know that at least I'm not the only one having this issue.

Having the exact same problem. So hopefully we ill get an response quicky for a solution. Its quite anoying not to be able to create your own costum puzzles :(

For some reason, I can't even save at all. When I try to sign-in or save or load, I get a message telling me:
"TIM 3 has been installed in a write-protected area. You cannot sign in."
I cannot unset the "Read-only" attribute for my TIM folder, either. Any ideas?

Montydrei: If you have Vista, like me, the way to solve that problem is to run the game as an administrator. I still am not able to save, but at least the game automatically saves my progress, and I can load puzzles from the puzzle screen (not the file menu).

I'm having the same problem as montydrei, and I'm on XP. It won't let me sign in, save custom puzzles, bring up the list of puzzles to see which I've completed...
This is rather problematic.
Update: it seems to work more or less fine in a Windows 3.1 environment under DOSbox, though.

Did you all install it in the default program files folder?
Then try install it in your documents folder or outside program files folder instead.

I tried moving it to C:\TIM3, which made no difference. Then I took the exact same unmodified installation and transplanted it into DOSbox whereupon it worked properly. I'm thinking it must be some general issue with XP.

Edit: didn't see all the other responses, trying them first.

Does anyone know how to do this? When I installed the option for installing dosbox was selected.