psacct needs to be updated for 2.2 kernels.  However,
the caveat is that the autoconf script for it is broken.
After doing a ./configure, the config.h looks like:

/* Define if you have the <linux/acct.h> header file. */
/* #undef HAVE_LINUX_ACCT_H */

instead of the necessary

/* Define if you have the <linux/acct.h> header file. */
#define HAVE_LINUX_ACCT_H

so, in addition to recompiling against 2.2 headers, you'll
also either need to patch the autoconf stuff or else add
a kludge to sed the config.h after it's generated.

Ask away if you have more questions.  BTW, I'm assuming
this is true for all architectures; I've only noticed it
on i386, but because of why it broke, it should be true
on everything.

later,
chris