I am having some issues with the way a new game I am working on (for the Unity Awards) performs. I tested the game dozens of times before upgrading and performance was consistent. As soon as I upgraded things changed rather significantly.
To give a little detail, I have two objects rotating around a central pivot point. The objects are also moving around colliding with other objects. In pre-2.1 testing the objects always stayed located around the pivot so that it is centered between them as I had wanted them to. Now, however, they very quickly stray off so that the pivot is far off to the side.
Has there been some change in Unity that would account for this? How should I approach getting this fixed?
Thanks.
Not that I’m aware of, maybe Sam/Joachim/someone else will chime in if they know differently.
Log a bug so we can look at a proper long-term fix if one is need. Post more details, perhaps a slimmed down sample project, here on the forums so we can look at offering some guidance.
I am working on following HiggyB’s advice but have encountered a weirder problem. When I opened up the project in 2.1 this morning Unity made me upgrade it again! This is the project that I was using in 2.1 for hours yesterday and saved in 2.1 multiple times! Can’t imagine what’s going on there…
Hold on! I closed the project again to open an earlier version (that had been opened and saved in 2.1 already) and when I tried to reopen the main project Unity is telling me I have to upgrade the project yet again!!!
I wonder if this is caused by my opening other projects in Unity 2 and running both versions of Unity at the same time…
The physics issue is fixed - one of the settings in the inspector was changed and kinematic was unchecked. I was able to find that by switching between the old Unity and 2.1 files. So I shouldn’t be running them together now and hopefully the other issue of needing to upgrade again and again will cease as well.
Just so you know, you should be exceedingly careful when having several versions of Unity installed, and especially when moving projects back and forth. Unity will warn you each time, and you should at least back up whenever you make such a move.
Upgrading should of course always work fine, but while downgrading sometimes might work just fine, it’s not something we strive to guarantee.
Also, never run several copies of Unity at the same time with the same project loaded.
d.
I see that and think, “Don’t cross the streams.” 
Definite chance of yangmeng getting seriously slimed.
Well, I haven’t gotten slimed and actually I did not downgrade my project - I made a duplicate of the project, upgraded one copy and ran the other copy in the older version - I didn’t think you could downgrade. But I did see that running two versions of Unity (with different projects) at the same time cause some, er, sliminess, so I will avoid it.
Thanks for the advice!