As of 2008-09-28, I'm running current Rawhide, including emacs-22.2-5.fc9.

When running under X, Emacs hangs almost constantly.  I have to save my work literally every 30 seconds or so.

Also, as I type, Emacs drops characters.  E.g., I typed the above line 3 times in an Emacs window, and this is what I got:

I have toave my work literlly every 30 seconds or so.
I have to save my workliteraly every 30 seconds o so.
Ihae to save my work literlly every 30 seconds or so.

When Emacs hangs, it accepts no input and does not refresh the screen. When I strace a hung Emacs process, I see the follow system call sequence whenever I manipulate the cursor in or attempt to type in a hung Emacs windows:

select(5, [4], [], NULL, NULL)          = 1 (in [4])
--- SIGIO (I/O possible) @ 0 (0) ---
rt_sigreturn(0)                         = 1
read(4, "\34y\327\24}\0\0\0\36\1\0\0\303\3500\1\0\0\0\0\0\0\0\0\1\0\0\0\0\0\0\0"..., 4096) = 32
read(4, 0x1182ae4, 4096)                = -1 EAGAIN (Resource temporarily unavailable)
select(5, [4], [], NULL, NULL)          = 1 (in [4])
--- SIGIO (I/O possible) @ 0 (0) ---
rt_sigreturn(0)                         = 1
read(4, "\34y\327\24}\0\0\0\36\1\0\0\316\3500\1\0\0\0\0\0\0\0\0\1\0\0\0\0\0\0\0"..., 4096) = 32
read(4, 0x1182ae4, 4096)                = -1 EAGAIN (Resource temporarily unavailable)
select(5, [4], [], NULL, NULL)          = 1 (in [4])
--- SIGIO (I/O possible) @ 0 (0) ---
rt_sigreturn(0)                         = 1
read(4, "\34y\327\24}\0\0\0\30\1\0\0\5\3510\1\0\0\0\0\0\0\0\0\1\0\0\0\0\0\0\0"..., 4096) = 32
read(4, 0x1182ae4, 4096)                = -1 EAGAIN (Resource temporarily unavailable)
[...]

Although I'm not too upset about this (this is Rawhide, after all), I wanted to make sure this problem was known...