Linux kernel RC2 was just released few hours ago. It has some bug fixes and additional drivers. You may want to try it in your Ubuntu 11.04 installation because it may solve problems and work good for you.
Don’t remove previous Linux kernel after installing it, new kernel may cause new problems and previous can be used for resume.
1.) Download the debs from http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.0-rc2-oneiric/
There are three packages need to install in this order: linux-headers-*-all.deb, linux-headers-*-generic-*.deb, and finally linux-image-*.deb.
2.) As you prefer, you can also download and compile the source code from http://www.kernel.org/pub/linux/kernel/v3.0/testing/
Once installation finish, reboot and it should be listed in grub boot entries. Just select to boot it. If you get into problems with this kernel, reboot and select to boot into previous Linux kernel and remove linux-headers-3 and linux-image-3 in synaptic-package-manager.
If newer versions are released, check out here