I'm running Ubuntu 11.04 on a Asus PC 1001P in a dual boot environment with XP.
All has been running fine for several weeks, but:
I've just changed ISP (from Tiscali to BT), and had already sorted out connection, registration, etc. on a Dell laptop. On the Asus I went into Ubuntu to alter the wireless network details (i.e. selected the new network, and entered the password). Ubuntu immediately started running slowly, and after rebooting it now freezes when it gets to the Ubuntu logo and gets no further.