Yes i´ve seen that too. As far as i can see that almost happens with image captchas like "10+2=?" and something like that. Seems they dont be able to calculate at shanibpo?! :-)
Well, i got in contact with them, and there exact words were:
Thank you for contacting us, I have just refreshed your account and I hope it wouldn't reject your CAPTCHAs any more.
Please try and run GSA again, please be advised not to run a burst of CAPTCHAs as our system has a DDoS protection in place which can again restrict access for you.
I was originally running on 2 VPS's, at 300 threads each, so probably overkill. I've set it back down to 100 threads per VPS, and things seem to be back to normal now.
Comments
Thank you for contacting us, I have just refreshed your
account and I hope it wouldn't reject your CAPTCHAs any more.
Please try and run GSA again, please be advised not to
run a burst of CAPTCHAs as our system has a DDoS protection in place which can
again restrict access for you.
I was originally running on 2 VPS's, at 300 threads each, so probably overkill. I've set it back down to 100 threads per VPS, and things seem to be back to normal now.