Migrated from 2.5.x to 3.1, modules still 2.5

[pi_wo]

Hi there,

I have just migrated Joomla from 2.5.11 to 3.1. Everything went pretty smooth, except, when I go to Extensions Manager and then Manage Tab, almost all extensions are still marked as 2.5.0. Only brand new extensions have 3.0.0 version

Is it normal ? If it is, it's a little weird to me. Can it cause some unexpected problems in the future ? I haven't tested it, but I realize that some of the core extensions may work and look pretty much the same as those in 2.5. Still I would strongly recommend updating joomla module versions as well (even if it only value in database) because it's a little bit confusing.

Subquestion:
I few months ago I created a new instance of Joomla 2.5 and manually migrated contents from another cms to that database (it was about ~60 articles and few categories). I wanted to create new website using J! 2.5 as it was more stable solution to this time. Unfortunatelly, I had to postpone webpage migration and now I would like to use J! 3 enviroment. What is better (in terms of performance, safety etc) option for me:

1) To migrate from Joomla 2.5 to 3.1 (as i already did) and accept those small glitches
2) Or to create clean Joomla 3.1 and put all the content manually again ( there is no modules, no components etc. so also no compatibility issues)

3) Or ... to create clean Joomla 3.1 enviroment and manually (using sql) move data from 2.5 database to the one with 3.1 as there are only articles and categories

Best regards
Piotr