emacs doesn't show characters in RHEL6.6

I'm using RHEL6.6 but emacs is behaving very strange. Letters disappear (doesn't show) while I write or scroll. I have to do Ctrl-L to refresh to see the letters. Extremely annoying and I can hardly use emacs anymore. Version on emacs is 1:23.1-25.el6. I downloaded a newer emacs and compiled it, but the problem persists. Could it have something to do with X or gdm?

I have been running RHEL6.4 for a couple of years and had no problem with emacs there. I attach two snapshots,
1) How it looks when I write or just move around with the cursor. Note that all spaces actually are chars.
2) Whe I reload page with Ctrl-L, the window looks like this. The characters are suddenly visible.

But as soon as I start write or move cursor, the characters will be invisible again.

emacs -q, emacs -Q or changing fonts won't help. What to do??? I love emacs but I can't use it when it behaves like this...

Not sure graphic card is relevant. I run RHEL6.6 out-of-the-box as a virtual machine in VMware, but it is exactly the same environment as I had in RHEL6.4 and there were no problems with emacs there.

After reload: