Computer stats:

Model: Everex GC2500 (desktop)
Processor: VIA Esther
Speed: 1500 MHz
Hard Disk Space: 80 GB
OS: Windows XP Service Pack 2
RAM: 960 MB

The problem:

Today I bought a 1 GB RAM chip, manufacturer Kingston. I already had a 512 MB chip, manufacturer A-Data Technology. My computer has two RAM slots. The 512 MB chip had previously been in the first slot. I went to insert the 1 GB into the second slot and had trouble getting it to go in all the way. I had been properly inserting it.

I took it to the RadioShack I had bought it from and the man who helped me also had to apply a decent amount of pressure to get it in. Then when he went to test the computer, it didn't recognize the 1 GB in the second slot. So he swapped them, putting the 1 GB in slot 1 and the 512 in slot 2. It recognized the 1 GB but not the 512.

When I use the program CPU-Z, it can recognize the RAM chip in slot two.

Is it possible that the second slot could be a dud or is there something else that could be going on?

(The reason I say I have 960 MB RAM is because my video card, a VIA/S3G UniChrome Pro ICP, uses 64 MB for itself.)