It returns when the next map loads but may not last long. This happens about 1 in 20 maps.
I am using Realtek High Definifion Audio drvr. 6.0.1.5864 and have the latest Win7 and driver updates.
About 3 characters displayed on each dialog are random bit patterns.
This seemed to happen after that last patch download.
Do these fall under the "Wait for next update" category?