Hi WinnieThePanda,
Many Test Takers spend 3 months (or more) on their studies before they hit their 'peak' scores, so it's likely that you just have not put in enough time and effort yet to score higher. Since there's a considerable 'range' in your CAT scores, I'd like to know a bit more about how you took those Tests:
When you took your CATs:
1) Did you take the ENTIRE CAT (including the Essay and IR sections)?
2) Did you take them at home?
3) Did you take them at the same time of day as your Official GMAT?
4) Did you ever do ANYTHING during your CATs that you couldn't do on Test Day (pause the CAT, skip sections, take longer breaks, etc.)?
5) Did you ever take a CAT more than once?
Many Business Schools have publicly stated that they do NOT use an applicant's IR Score when reviewing an application, so you likely have nothing to worry about in that regard. IR performance combines a lot of the same CR skills with some math skills (on certain questions), so improving on CR will likely improve your IR too.
The Q41 means that you were pretty good at most of the 'math' questions that you faced in the Quant section, but you made a bunch of little mistakes on 'gettable' questions and you missed out on a lot of 'strategy-based' points. The V36 means that you were likely solid in all three major Verbal categories, so your missing points there will likely be found in some of the rarer question types, understanding the common wrong answers (so you can spot them and avoid them), etc.
GMAT assassins aren't born, they're made,
Rich