Isn't Ruger replacing some of the older SR9's triggers? Their web site shows it as a recall their doing. See the info below from Rugers web site:
SR9 RECALL
UPDATE
We have determined that some Ruger SR9 pistols manufactured between October 2007 and April 2008 can, under certain conditions, fire if dropped with their manual safeties in the "off" or "fire" position. The pistols will not fire if the manual safety is in the "on" or "safe" position.
We will retrofit all affected SR9 pistols (those with serial number 330-29999 or lower) with these parts at no charge to our customers. In order to ensure correct fitting, the new parts must be installed at our Ruger factory in Prescott, Arizona. We will remove the old parts and install the new trigger group promptly, at no charge, and will return the pistol to you. The old parts will not be returned.
We have resumed production of SR9 pistols and the "330" prefix remains the same in both the original and newly manufactured pistols. However, newly manufactured SR9 pistols have serial numbers of 30000 or higher (that is 330-30000 or more) and original SR9 pistols have serial numbers below 30000 (that is, 330-29999 or less). Of course, if you purchased a used SR9 or recently purchased a new SR9, it may already have the retrofit parts.
It is easy to determine if your pistol has been retrofitted by simply looking at it. Although both the old and new trigger group have a two-stage trigger, the original design had an inner "shoe" that was not visible and, therefore, appeared to be a single trigger (See Figure 1, below). The new trigger design incorporates a visible inner trigger of a blade design (See Figure 2, below).
Go to Ruger.com, at the bottom of the site page it has a box that states: SR9 Recall, click-it!!!!