internal server error for search "price:[0 to 5]"

http://www.archive.org/bookservercatalog.php/search?q=mind+AND+provider%3AOReilly

[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] Traceback (most recent call last):
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/web/application.py", line 242, in process
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] return self.handle()
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/web/application.py", line 233, in handle
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] return self._delegate(fn, self.fvars, args)
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/web/application.py", line 412, in _delegate
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] return handle_class(cls)
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/web/application.py", line 387, in handle_class
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] return tocall(*args)
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/www/bookserver/aggregator/opds_aggregator.py", line 383, in GET
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] titleFragment = titleFragment)
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/bookserver/catalog/ingest/SolrToCatalog.py", line 152, in __init__
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] obj = json.loads(contents)
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/simplejson/**init**.py", line 307, in loads
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] return _default_decoder.decode(s)
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/simplejson/decoder.py", line 335, in decode
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] obj, end = self.raw_decode(s, idx=_w(s, 0).end())
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] File "/petabox/sw/lib/python/simplejson/decoder.py", line 353, in raw_decode
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] raise ValueError("No JSON object could be decoded")
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39] ValueError: No JSON object could be decoded
[Fri Oct 16 22:57:34 2009] [error] [client 207.241.229.39]