CTR represents clickthru rate. It is the percentage (sometimes represented as a decimal, however) of those viewing the ad who click on it. Average CTR has been publicized to be about 0.5% for banner ads, and as much as four times that (2.0%) for text-based advertising.
Your absurdly large results are probably skewed because of few impressions. For example, if an ad is only viewed four times, and one person clicks on it, that is instantaneously a 25% CTR. However, it is incredibly unlikely that it remains consistant that for every four ad views, there will be a click.
I hate to unfortunately burst your bubble, but the more you continue to use Clicksor, the lower your CTR will be, as it slowly falls more into the norm and eventually locks into place, once there is an appropriate sample size to work with.
Simply improve your ad - make it more compelling for searchers to click.
A few tips:
1. Make sure that your keyword/phrase appears in the title. This is a MUST.
2. If possible the word/phrase should appear in the copy of the ad.
3. Test multiple versions of your ads to see which ones perform best.
4. Use a call to action.
You can never lock in a click through rate....26% is a very high click through rate. Be happy with it and embrace it! You will never get the quality or volume of traffic via 2nd tier search engines...work on expanding your keyword list. Keep your bids low until you see some conversions coming in, then you can beef up your bids!