If you have a CLIQ, it's probably a good idea to hold off on any updates, as a multitude of issues have cropped up. And most importantly, a T-Mobile forum mod recommends you "not to Master Reset your phone if your OTA update did not download or if you are experiencing issues at this time." [T-Mobile forums via Android and Me via BGR]

UPDATE: From Motorola:

Last week, the CLIQ 1.3.18 over-the-air software update began rolling out to consumers. While the vast majority of updates were successful, a very small number of consumers reported a date error and found that, after factory resetting their device, their phone was not functioning properly. We have identified a workaround solution for these consumers, which can be found on the Motorola support forum (http://direct.motorola.com/hellomoto/us/support/tmo/index.html).

To our consumers, we apologize and are working swiftly to reconcile the situation. We are also revising the over-the-air software update so that this workaround solution is no longer needed. Consumers will be notified on their device when the revised update is available.

If you would like to provide more guidance to your readers, below is additional information for consumers:

To our consumers who downloaded the update and their device is working properly, no further action is needed. To our consumers who never received a notification to download the update, please do not take further action. You will be notified on your device when the revised update is available to you. To consumers who received an error or whose device date reads December 31, 1969, please visit the support site listed above for assistance.