First thing to do is create a current backup to give you a recovery point is something goes astray. I would address this using a Portfolio View (Ctrl-U) showing shares, cost basis and Market Value. Cycle the As of date back in time to determine when the data last matched correctly. Then for the date showing the error, delete and re-enter any applicable transactions for that MM fund. Repeat as necessary for other dates. If that does not fix things, I would validate (File Operations) including the rebuild lots option.Post back if neither of those fix the issue.
In addition to the above, all of which I concur with, I'd turn off the download of prices/quotes for the MMF.It's probable that a stray/erroneous quote is the cause of the erroneous RlzdGain ... and after fixing the matter you can prevent it going forward by simply NOT downloading quotes for a MMF.Do CTRL-Y, select the MMF and UNcheck "Download Quotes".