Thanks Jester,
I will definitely give it a full charge before getting up again.
I plugged all my servos in, and the battery still turns them in spite of being on all night. Guess it isn't the battery after all.
I spoke to someone who repairs JR radios and he thinks I may have damaged a filter in the rx in a previous crash and this might be causing the intermittent failures. I am going to buy a new rx today and see if that fixes my problem.