solr - using fq parameter does not retrieve an answer

[Mysurf Mail]

When I query using

http://localhost:8983/solr/vault/select?q=*:*

I get reuslts including the following

<doc>
  ...
  ...
  <int name="VersionNumber">7</int>
  ...
</doc>

Now I try to get only that row so I add to my query fq=VersionNumber:7

http://localhost:8983/solr/vault/select?q=*:*&fq=VersionNumber:7

And I get nothing.
Any idea?