The agonizing I mentioned in the original post was between a D7000 and a D7100. I tend to keep my cameras for a while so didn't want to buy a camera with four year old technology! The D7000 seems to be an excellent camera and I think it would be more than adequate for my amateur pursuits but the aging technology makes me want something newer.

Thanks Phil. As I mentioned I am frugal so a drop in price of $200 would be worth the wait. However your point is well taken. "Why wait?"

After much agonizing I decided to buy a D7100. I have been an amateur photographer since 1970 when I bought a Canon FTQL which served me well until about 2001 when it started to give me trouble. At that time I decided I wanted to switch to Nikon and bought an FM3a along with several lenses most of which were manual except for a 50 mm 1.8D. In the following years I bought a Nikon N90 and several medium format cameras. I also have a black and white darkroom which has been largely neglected for the last few years!
In 2010 I bought a Canon S90 which has represented most of my photography. My wife and I enjoy long distance hiking and we walked the Tour of Mont Blanc twice. This is an 11 day 105 mile trek where you carry all your own gear and stay in mountain huts (refuges). The point here is that it is important to minimize the weight carried so the S90 was perfect.
I am about to turn 70 so I thought that a worthy present would be the D7100.
The problem is that I am frugal (actually cheap would be a better description). I have read that Nikon may bring out the next version of the D7100 in the fall which could result in a reduced price.
The purpose of this long-winded diatribe is to see if anyone can remember the price deduction in the D7000 when the D7100 was announced. I am wondering if it is worth waiting? I don't feel any urgency in this purchase.
Any information or advice would be appreciated.
Thanks. Dave

You need to decide what your priorities are regarding weight, convenience and image quality.
My wife and I have trekked around Mont Blanc in the Alps a couple of times. A link to a trip report is http://hiking.topicwise.com/doc/MontBlanc2012
We used a Canon S90 that is very light and easy to carry. I used a small case that easily fit on the sternum strap of my backpack. Obviously more up-to-date point and shoot cameras are now available. It is very inconvenient to have to open your backpack to retrieve your camera.
Here is where priorities are important. Last year we camped and day hiked at Glacier National Park and used the S90. It was great for landscapes but not so great for wildlife photos due to the limited telephoto range.
My son-in-law has the Canon SX50 which has impressive range but would not be convenient to carry on a sternum strap.
If weight is a priority a DSLR may not be the best choice. I believe the current version of my camera is the S120. Other manufacturers has similar offerings of equal quality.
To summarize, decide how much weight you want to carry, how convenient your carrying method should be, how much reach you want (wildlife are often far away), and what image quality you want. Another factor is if you want to shoot in RAW.
Don't forget that if you are camping you may not be able to recharge batteries so you will need to carry spares.

You may have oxidized contacts. If the problem occurs for the same card in either slot then the problem would be the card's contacts. A pencil eraser can be used to clean contacts.
If the problem occurs for both cards in only one slot then the problem would be the slot's contacts which are more difficult to clean. You can buy an electronic contact cleaner in a spray can. Radio Shack would be a source or other electronics store. Use sparingly!
Hope this helps.

You have received plenty of excellent suggestions. Assuming you are willing to build your own computer there are several useful websites for part selection and building advice.

http://www.tomshardware.com/ is a site with a wealth of information.

http://pcpartpicker.com/ is a site which gives you a template for selecting various parts including cheapest places to buy , it keeps a running total of power usage and also advises you if some of your selections are incompatible.

Several people have mentioned Linux as an alternative operating system. I would advise caution because Linux has limited applications available. Not many (if any) of the most popular post-processing programs are ported to Linux. There is always Gimp but Photoshop and similar utilities are not available.

I recently bought a Wacom tablet from BH Photo for about $90. It came with several relevant software packages including Elements 11. He might enjoy the tablet. Of course, if he already has a tablet just ignore this suggestion. :)