I'm afraid I'm not able to pin down any similar behavior on any of our installs. Though it's a pain to do so, have you tried deleting your Wizard 101 bottle (which you can do inside Crossover's Configure>Manage Bottles menu, using the "-" key) and then re-installing a brand new copy into a new bottle?
After the install it'll take some time to re-load all of your character data, but a subsequent test will tell you if the problem is some kind of corruption with the bottle (which we haven't seen before, but is likely) or some problem with Wizard 101, itself - perhaps with the servers that your client accesses.