Different Service Pack Levels

What sorf of "bad things" can happen if a client at a service pack level accesses an Enterprise server or deployment server at a lower service pack level. For instance, an SP20 client checks in a version when the Enterprise server and deployment server are at SP18

This could potentially happens in our environment because we have clients with DV, PY and PD and ususually apply service packs to DV and PY a day or two prior to applying it to PD.

Corrupted specs. Service Packs are Foundation code changes. You don't want to mix and match. JDE has a way to setup multiple foundations, see the document on the knowledge garden.

You should consider multiple foundation on your sustem, that way you cantest the service pack and only affect one env. then roll it out to your live env's at the same time.

You have have spec corruption if you promote across different SP levels.

Thanks to those of you who took the time to respond.

We do use multiple foundations, but usually do not apply a SP to all environments simultaneously after testing. However, it sounds like simultaneous application is the only way to minimize our exposure.

Thanks again.