I looked for logcontract and did not find a bug like this:
Maxima version: 5.22.1
Maxima build date: 11:48 8/13/2010
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8
intval:integrate(1/(2+4*x^2+5*x^4), x, 0, 1)$
logcontract(intval);
gives a message that maxima.exe is not working any more (see http://dl.dropbox.com/u/3030567/MaximaDies.png\)
I'll try the same under linux shortly.
logcontract (intval);
=> overflow during multiplication of large numbers
Maxima version: 5.22.1
Maxima build date: 22:6 8/11/2010
Host type: i686-redhat-linux-gnu
Lisp implementation type: CLISP
Lisp implementation version: 2.48 (2009-07-28) (built 3459348196) (memory 3490574775)
Observed in post-5.46 with GCL, which runs into an out of memory error. I suspect at the root it's the same "numbers too big" error as shown by Clisp.