I have used the 305 since last September and I'm having an issue with something that doesn't make since. Back in October I rode a century and it recorded all the info perfectly except the mapping. It only recorded the last 52 miles. Today I rode the Tour de Palm Springs and it did the same thing, dropped the first part of the mapping and recorded only the last 68 miles. Is there some sort of default amount of mapping info it can hold or what? Anyone else having the same problem?