Bought one a few months ago and I've been very happy with it -- but just found this today. Basically if it was produced before June 1 (i.e., you own it), there is a recall. Apparently a hickup can occur if the safety is between safe and fire.
We recently received a small number of reports from the field that Mark IV™ pistols (including 22/45™ variants) have the potential to discharge accidentally if the safety is not utilized correctly. In particular, if the trigger is pulled while the safety lever is midway between the "safe" and "fire" positions (that is, the safety is not fully engaged or fully disengaged), then the pistol may not fire when the trigger is pulled. However, if the trigger is released and the safety lever is then moved from the mid position to the "fire" position, the pistol may fire at that time. We have conducted additional testing and have confirmed this condition. Because we are firmly committed to safety, we would like to retrofit all potentially affected pistols with an updated safety mechanism.
https://ruger.com/dataProcess/markIV.../index.php?r=y