EM-411 GPS stuck in debug mode?

I've successfully connected an Arduino to an EM-411 GPS unit, and I get the initial "$GPGGA" over serial.

However, after the "$GPGSV" message arrives, the GPS starts outputting bogus data (dollar signs with intermittent numbers and letters). Occasionally it will output a "$PSRFTEXT" message, followed by the version number. I believe the GPS might be stuck in a debug mode of some sort, but I haven't found any resources on how to fix it.

Am I correct in assuming that the GPS is at fault, and not the serial link?

(sorry for the lack of details, I'll update this later on)

Problem solved! Using version 0022 turned out to solve the problem, most likely because of the older software serial library :~

Problem solved! Using version 0022 turned out to solve the problem, most likely because of the older software serial library

Because you are now using the older library? I don't see how that solves the problem. What code are you using?