One of my users just reported an error searching for
just numbers (or
numbers with punctuation).  I tried and found that
quoting the numbers
does not help.  This is a 0.7.9 installation with
MySQL.  Search for just
'22' returns:

_mysql_exceptions.ProgrammingError: (1064, "You have an
error in your SQL
syntax. Check the manual that corresponds to your MySQL
server version for
the right syntax to use near ')' at line 1")

Debugging information follows

   1. While evaluating the standard:'request/batch'
expression on line 13
      Current variables:
      templates	<roundup.cgi.templating.Templates
instance at 0x83f9e0c>
      repeat
<roundup.cgi.PageTemplates.TALES.SafeMapping instance at
      0x840650c> template	<Roundup PageTemplate
'issue.index.html'>
      default	<roundup.cgi.PageTemplates.TALES.Default
instance at
      0x8200b2c> db
<roundup.cgi.templating.HTMLDatabase instance at
      0x843f9ac> utils	<roundup.cgi.templating.utils
instance at
      0x844035c> request
<roundup.cgi.templating.HTMLRequest instance at
      0x840b8c4> tracker	<module '_roundup_tracker_1' from
      '/var/lib/roundup/tracker/__init__.pyo'> context
      <HTMLClass(0x83f862c) issue>
      nothing	None
      config	<module '_roundup_tracker_1.config' from
      '/var/lib/roundup/tracker/config.pyo'> options
{'ok_message': [],
      'error_message': []} loop
      <roundup.cgi.PageTemplates.TALES.SafeMapping
instance at 0x840650c>
      attrs	{'tal:define': 'batch request/batch',
'tal:condition':
      'context/is_view_ok'}
   2. A problem occurred in your template
"issue.index.html".

Curiously enough, searching for '000' does not give the
error; '00',
'0.0.0' and '0' does.