Q: Multiple Macs running 10.10.1 and IPhones having wi-fi drop outs and web pages not accessible

For the last 2-3 months, our internet access has become spotty on our Apple based products.  Both our 27 inch IMac and new Power Book Pro run 10.10.1.  I recently upgraded the IMac to 10.10.1 thinking that this might fix the problem. It did not.  Both IMac and PBP are up to date with all software updates.

Access to web pages is very spotty.  Happens on both the IMac and PBP.  Same signature.  Also, five of the IPhones (4s and 6s) are experiencing similar problems in accessing the web via Wi-Fi.

Signature is that when requesting a web page, we instantly receive a web page not available warning.  Multiple clicks sometimes produces the web page.  Sometimes waiting and re requesting will work.  No noticeable pattern to when a web page, e.g., Google, is available and when it is not.  Very frustrating.

Weirdest part is that the three PCs in the house have no trouble getting WI-FI connection via our Netgear dual channel wireless router.  Rock solid and very consistent behavior.  What might be causing this wi-fi access problem with Apple products?

Could there be some kind of new incompatibility issue with the Netgear wireless router?

Many thanks for any help!