If you have real trouble in interviews and you think this is a long-term issue that you can't address, you need to make your paperwork so strong that it is obvious to the interviewers that you are a poor interview performer rather than an ignoramus. I keep harping on about this, but one way of doing this is strengthening your open source or other easily verifiable credentials.

Secondly, try and apply for jobs (if you have this choice) to places that don't do "monkey trick" interviews but screen using other techniques, like code submissions. (This is one of the many reasons I prefer the latter to the former)

The point about power dynamics in the link below might also be helpful:

http://askamanager.blogspot.com/2010/05/how-can-i-stop-being...

[Later edit: Since you said elsewhere that this is a problem only during interviews, make sure your reference letters mention you are a good communicator or problem solver or whatever, to indicate that anything the interviewers see is not typical]