X server crashes in Raring [13.04] but not Precise [12.04 LTS]

[chandra]

I run Kubuntu off either of two partitions, one with Raring (13.04) and the other with Precise (12.04). The performance on Precise is rock solid, but with Raring, the X server crashes on me unpredictably. I lose mouse and keyboard control and get a grey screen that requires a hardware restart. The crashes occur even when keyboard or mouse are in use, rather than out of use. Although I have filed this under the X-server, I cannot rule out some application like kile or kate leaking memory and contributing to the crash or even causing it.

Some forums suggested that power management might be the issue; others talked of problems with the radeon driver; yet others said that the x-server package in Raring had introduced some changes/problems. I am unsure which of these, if any, applies to me.

To start things off, video is on the motherboard, and this is the condensed hardware info:
---
description: Motherboard
product: M5A78L-M LE
vendor: ASUSTeK Computer INC.

description: CPU
product: AMD Athlon(tm) II X2 260 Processor
vendor: Advanced Micro Devices [AMD]

description: VGA compatible controller
product: RS780L [Radeon 3000]
vendor: Advanced Micro Devices [AMD] nee ATI
physical id: 5
bus info: pci@0000:01:05.0
version: 00
width: 32 bits
clock: 33MHz
capabilities: pm msi vga_controller bus_master cap_list rom
configuration: driver=radeon latency=0
resources: irq:18 memory:d0000000-dfffffff ioport:d000(size=256) memory:feae0000-feaeffff memory:fe900000-fe9fffff
---

My system settings for power management are as shown in the attachment.

I would be most grateful for suggestions on troubleshooting and solving this problem.

Thank you.

[Snowhog]

Are you sharing the same /home partition between both 12.04 and 13.04?

[chandra]

Yes indeed, I am sharing the same /home partition between 12.04 and 13.04.

If this is the cause, how might I avoid duplicating and synchronizing all my document files etc., if I have to maintain separate /home partitions?

Is there a way of "decanting" the sensitive files elsewhere so that the common files can be kept in one place?