josh,
i mainly use telescopics for bc snowboarding. i bought a pair of komperdell titanals and experienced this problem as well. a few things on the subject:
as tom mentioned, begin by taking them apart and relubing them, perhaps even replacing the parts...i think you said they are ems...the parts should be easily available. see if this remedies your problem.
if this does not work, a question: how hard are you weighting down on your poles? (not a judgment, just a question) this is important because there are a few possibilities with the telescoping devices:
1. undertwist/turning the pole - in this case, simply twist them a bit firmer, perhaps a 1/4, 1/2 or full turn. this should keep them from collapsing when they should be in "fixed" mode. (i know this is pretty obvious, but worth mentioning anyway-no disrespect intended).
2. overtwist/turning the pole - effectively, the opposite problem, where you are overloading the mechanism which is usually plastic and will strip and collapse if overturned. simply don't twist them as firmly. if you are having much difficulty untwisting them when trying to collapse the poles this may be your problem. perhaps a 1/4, 1/2 or full turn less. this should keep them from stripping and collapsing when they should be in "fixed" mode.
3. overweighting - if you are really levering considerable body weight on your poles this will again, overload the plastic threading system to failure and they will strip and collapse. at this point, if this is your problem, and you think you need to use the poles in this manner, i would suggest a different type of pole such as the black diamond flick-locks.
i switched to these from the komperdells because i experienced continued failure. as it turns out, i simply overweighted the k-dell system which isn't designed to do what i was doing. wrong tool for the job. the bd expeditions are beefy, cost around $80 and should stand up to all abuse without the telescopic failure. they have an external locking device which cams the two pole halves much more securely and will generally not fail, at least i haven't had them do so yet. however, they do not have a shock-absorber, being that they are usually used for ski/snowboard mountaineering, not really hiking/trekking poles.
there are other brands which use other locking systems, life-link comes to mind. they are pricey but do have shock absorbers and the lekis are supposedly good, though they do use a similar plastic threading mechanism to the ems poles you currently have.
good luck, hope this helps.