SIMBAD parsing warning / error only emitted once?

I tried executing the examples in the SIMBAD tutorial.
https://gist.github.com/cdeil/6208542

The queries with radius 5 deg time out most of the time after 60 sec ... maybe change to a smaller query radius?

Another issue I noticed is that the following warnings are printed the first time the query doesn't time out:
```
In [23]: result_table = Simbad.query_region("m81", radius=5 * u.deg)
WARNING: Warning: The script line number 3 raised the error: IO error while adding the object list in the VOTable: null . [astroquery.simbad.core]
WARNING: Error in parsing Simbad result. Returning raw result instead. [astroquery.simbad.core]
```
but then next time a query returns raw results there is no warning / error that the returned result is not a valid table:
```
In [27]: result_table = Simbad.query_region("05h35m17.3s -05h23m28s", radius='5d0m0s')
WARNING: Coordinate string is being interpreted as an ICRS coordinate. [astroquery.utils.commons]
 
In [28]: result_table
Out[28]: '::script::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::\n\nvotable {main_id,coordinates}\nvotable open\nquery coo  5:35:17.30000 -80:52:00.00000 radius=5d frame=ICRS\nvotable close\n\n::console:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::\n\nC.D.S.  -  SIMBAD4 rel 1.207  -  2013.08.12CEST07:56:14\ntotal execution time: 29.173 secs\nsimbatch done\n\n::data::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::\n\n<?xml version="1.0" encoding="UTF-8"?>\n<VOTABLE xmlns="http://www.ivoa.net/xml/VOTable/v1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ivoa.net/xml/VOTable/v1.2" version="1.2">\n<DEFINITIONS>\n<COOSYS ID="COOSYS" equinox="2000" epoch="J2000" system="ICRS"/>\n</DEFINITIONS>\n<RESOURCE name="Simbad query" type="results">\n<TABLE ID="SimbadScript" name="default"><DESCRIPTION>Simbad script executed on 2013.08.12CEST07:56:14</DESCRIPTION>\n\n'
```
I think a warning or error should appear for every query that returns invalid results?