ha, I had this same problem actually, in september (and if I'm not mistaken into oct. as well.) Funny because ever since I first got it (about a year previous to this issue), I'd get the white "screen of death" and/or random crash-reboots at least once every few days! It started turning into several times a day, then was doing exactly what you're describing...then it also began to only be functional when it was plugged into my laptop USB. I'd unplug it, it'd do the four-lights-blink-crash cycle again. If I plugged it into the wall, it didn't seem to detect that at all and continued the same as when unplugged; a few days or maybe a week later, I had no network signal! It said the radio is off, after multiple reboots it was still saying it was off, I couldn't enable wifi or bluetooth either...
I had a one-year insurance plan from virgin mobile, so I called them about it and after two excessively long and unnecessary walkthroughs, backed up my stuff and downgraded to the next lowest OS b/c he said he thinks the latest one has more issues...didn't work. He had me ship it back to them and I got a replacement. Which is what I'm using now, and the first one I got at radioshack; the batteries actually are different, at least in labeling. This VM-labeled one though, I'm willing to bet hasn't caused me as many white screens in the past year as my first one did in a few months.... (Slacker has been crashing the thing lately but that's irrelevant here I think..)
I've also had issues, with both phones, with chargers not working, or constantly going between connecting-disconnecting (both Windows and Mac have given me repeated pop-ups that I unplugged the phone, pretty much every time I'd move it...
I'm making a separate post about that, but what worries me is that the last time I used an A/C charger, the phone lost its ability to charge entirely, and it happened to coincide with my computer crashing/hard drive malfunction.... directly preceding a kidney infection that came out of nowhere.. anyway, suffice to say technology pulverized my GPA last semester and now I'm twice as pressured about grad school!!
So all that said, lol I'd say replace the phone. Are you in a warranty of some sort that will replace it for free?
Because between my BB and my laptop, I feel I was entitled to a completely free (shipping + taxes included) replacement of each.

But I didn't get the laptop, because I stupidly took care of it well enough that it was okay until it was well out of the first year...