This doesn't sound like an issue I've heard reported before. WDE (and PGP Desktop in general) doesn't really perform many specific actions related to power events (such as resuming from sleep).
The most likely impact is that WDE introduces some overhead to disk accesses which might slow down disk activity to a certain degree. This might make a problem that existed before you encrypted seem more severe after you encrypted.
There are many non-PGP-related reasons why a system could behave the way you describe - the best approach that I can suggest is to try to identify other possible culprits and try disabling them. The alternate path would be to try to decrypt and deinstall PGP WDE, but as that's rather time-consuming it may be easier to start with other software.