AsyncGetCallTrace fails Error: guarantee(VerifyBeforeGC ..., "too expensive")

A snippet from an e-mail thread from Jeremy Manson at Google:

> This is happening in JDK6u6 32-bit. The error is that an assertion fails:
>
> # Internal Error (genCollectedHeap.cpp:867), pid=1813, tid=3454659504
> # Error: guarantee(VerifyBeforeGC || VerifyDuringGC ||
> VerifyBeforeExit || VerifyAfterGC,"too expensive")
>
> This is client VM, serial GC. It's always possible that I'm doing
> something wrong, too.

And another snippet:

> My environment is 32-bit JDK6u6 running on a Linux 2.6.18 kernel on
> top of a 2-processor P4 3.4GHz.