I've got the same problem but in my case it was permanent.
The fixed I used was too launch windows manager from startup
Fully up to date patched Ubuntu 10.4 latest kernel installed.
Dell laptop 1545 specs as follows
Intel® Pentium® Dual Core™ T4400 (2.2GHz/800Mhz FSB/1MB cache)
Genuine Windows® 7 Home Premium, 64bit, English Well no dual boots Ubuntu
Glossy, widescreen 15.6 inch display (1366x768)
8X CD/DVD Burner (Dual Layer DVD+/-R Drive)
4GB Shared Dual Channel DDR2 at 800MHz
250GB SATA Hard Drive (5400RPM)
Intel Graphics Media Accelerator X4500HD
Dell 1397 Wireless-G
I think the problem may have started after the last two kernels.
I've got the same problem but in my case it was permanent.
The fixed I used was too launch windows manager from startup
Fully up to date patched Ubuntu 10.4 latest kernel installed.
Dell laptop 1545 specs as follows
Intel® Pentium® Dual Core™ T4400 (2.2GHz/800Mhz FSB/1MB cache)
Genuine Windows® 7 Home Premium, 64bit, English Well no dual boots Ubuntu
Glossy, widescreen 15.6 inch display (1366x768)
8X CD/DVD Burner (Dual Layer DVD+/-R Drive)
4GB Shared Dual Channel DDR2 at 800MHz
250GB SATA Hard Drive (5400RPM)
Intel Graphics Media Accelerator X4500HD
Dell 1397 Wireless-G
I think the problem may have started after the last two kernels.