The OP solution Did not work for me.
However, the number of crashes seems to be less frequent, when I switch off the WiFi.

I haven't had any reboots when charging. However, I did notice that when switched to 2G mode only I had a few reboots. In 3G no issues at all.

It has to be network selection. We have a deadzone at work and it reboots like crazy whenever I'm in there. Outside of that area it is fine.

I agree with this theory over the media card bbthumbs.dat (although I am sure that corrupt bbthumbs.dat's do clear it up for some).

From reading elsewhere, 3G seems to work okay, but the handoff from 3G to 2G does not and causes a reboot. To test this, I switched to 3G only, and so far no reboots. I am going to test it further and go 2G only after I have given it sufficient time to confirm this. If that works, I will try 2G & 3G again, and if the reboots resume, I will keep it on either one until the next 5.0 (leaked or released).

Update: 2G only rebooted, so staying on 3G only (which if I understand, AT&T users cannot set their BB's to, as the option is not there).

If you do a back-up through Desktop manager, can you then format your memory card then restore to the media card what was backed up on DM?

We don't have a 3G network here as yet.. so.. I'm stuck on 2G >.>

As I got the drives showing up in My Computer now, I'll try formatting again.

Just formatted. No reboots since :P :) LOL

Well no reboots since yesterday... However. i do suspect it rebooted on me while I was sleeping... But, regardless.. No reboots so far :D

I have had no reboots since T-Mobile's outage.

More reboots . yay -.-

no fix yet....

As stated before. This is a BETA OS that is not officially released. There will not be an official fix. You have two options available to you. You can either go to a previous release, or go back to an officially released version supported by RIM and the Carrier.

My phone just rebooted like 4 times within the last 5 mins. I can't take this anymore.Back to .238.

I've tried everything mentioned, and still had numerous reboots. (No wifi, bt, 3G, only EDGE.) Went back to .130 (yay tabbed browsing).

I have had some rebooting issues but all of a sudden it has rebooted 6 times in the last hour, too! I may have to go down :(

maybe this is it ? Fix 5.0.0.314 reboots on Bold!
 

yesterday I disabled the "bedside mode" of the 9000.
no restarts since 24hrs - using 2G and wireless.

That does not mean, this fixes the problems, could be just coincidence + random luck.

But, if you like, try it out.

I have had Random reboots using that os i downgraded back so there is a bug in 5.0 yet ;-)

Right, I also experienced this, but not as many as with this version. I had maybe 1 every 3 days, now, i had up to 10 each day.

to early - today morning the device had again rebooted itself - this is also not a real fix.

After rebooting 4 times in 5 minutes, I could not take it anymore and went back to .238...

Waiting patiently on another leak / official os