I have the HP Deskjet Ink Advantage 3545 eAIO. I had set it up earlier this month and it was running just fine (AirPrint, et al). However, when I tried to print sometime back, my Macbook Pro wasn't able to detect the printer. The only change I'd done since the last successful print (yesterday) was to turn on the firewall. Reverting the change didn't help either. The funny thing - the printer's web login showed that the device was ready and working fine. However, the status in the Printer's desktop utility showed "unknown". At that time, I noticed that the driver version was 3.2.1 (same as the one mentioned in Apple's website knowledge base: http://support.apple.com/kb/HT3669) Seeing that nothing was working, I chose to "reset printing systems" in the Printer menu (System Preferences). I re-added the printer (through USB, Network address and Wireless detection). The configuration went well and I was able to print again. But I also noticed that the printer driver had been downgraded to 2.0 Question: How do I update it to 3.2.1? Re-downloading the printer driver/software from HP product support doesn't help. On a side note - The KB article says the update will show in the App Store. Try as I might, the update doesn't show up. Question: Is there anyway to manually download and install that particular update again (something similar to what Microsoft offers with Windows)? Thank you, in advance, for your suggestions.