Dale: if only it were that simple... The phenomenon Ian has tried to explain (and when you make it into the exciting world of online flying, you will discover for yourself) is the rapid and massive wind shifts we often encounter online - I've been on the receiving end of a shift of 180deg in a few secs before now, and it does indeed play merry hell with your IAS.
Ian: you can mitigate the problem somewhat if you happen to own the paid-for version of FSUIPC, it can do weather smoothing; changes in pressure and wind can be limited. Without paid for FSUIPC, if you like your real-world weather and are prepared to pay, the current Active Skies incarnation also has in-built weather smoothing (and it works better than FSUIPC's smoothing, by averaging winds across a vast area).
Otherwise, you're going to be stuck with the overspeed penalty as it exists now for a while yet. The next generation flight logger that's being worked on now has just entered alpha testing, and we are not going to be in a position to "lock down" the penalties in the new version for a while yet (but we are all aware within the MT that the penalties as they currently exist do need changing).