When is it better to add a theme, at creation of a store or later on, it makes no difference?

[HH Services Limited]

Hi, I am about to create a new site and I remember that once, I was testing a free theme and after installing it 50% of the already installed modules got unhook or disabled. Was this normal and I had to re-enable them? Also, is it better then to add a theme at the begginning of creation of a shop better than later on, or it makes no difference?

Any other tips for a first time theme installation?

 

Thanks, much appreciated your help.

[unlimitedgrain]

I think your first sentence of your post give you the answer!