Which I feel the same. I mean getting frustrated with a broken recaptcha for 300 sats sometimes make me feel uninterested to solve it again.
I think you just can keep on refreshing it right? So it wont be a problem at all. There is nothing like unsolved captcha right? For now this one is better rather than ask us to put the some words, sometimes words really trick my eyes, even no one can answer it when I ask everyone in my house. Pictures will be better, may be just some minor bugs that let us keep on clicking the same thing over and over
First of all you must keep your PC system updated, because it may cause abnormalities as you use it and maybe thus problem encountered literally one of the factor that certain problem was experienced. Don't ever lose hope because you can solve it as long as you look closely to the image and analyze the tricky puzzle which you felt difficult to recognize from captcha image. So you can really earn satoshi as you go further that captcha job, but it isn't easy thing that's why patience will be better for that.
That's not worthy to work with and yet there were many ways to earn bitcoins not just that free but a time consuming activity, specially when you internet connection is going bad it's really a disappointments with your work. Now you must choose good options after this recommendation of mine, participate here in bitcointalk forum so that you can establish your account post quality and apply for signature campaigns or any campaign that fits your comfort. Earning free bitcoin can be so boring and your efforts was just so extreme compared when you earned from the micro jobs at services section; I think that's more profitable.
Captcha images are not meant to trick you or to make it difficult to solve them.
They exist for the simple reason, to make sure that you are not a bot, It asks you to retype or to solve something that is VERY easy, but only a real human can solve, and it will be impossible for a bot to do so.