Students of martial arts may be familiar with a breakfall, which can (depending on the situation) be treated as a noun or a verb.
I am often amused when speakers, even native English speakers (myself included!), stumble over the past tense because of the double-irregularity. I've heard breakfalled, breakfell, brokefall, and brokefell - most try one combination or another and then switch to did a breakfall.
I was wondering if people had other examples of this phenomenon, and whether there is a canonically correct past tense form?
EDIT: Prompted by the discussion, for those interested, a breakfall may be defined as any of several ways of 'receiving' a technique, but in Western parlance most often refers to a method of slapping the ground (mat) just at the moment of impact, when you are thrown. This provides a reactive force and lessens the whole body impact if you are unable to roll out. (See uke/ukemi for the Japanese perspective).