I posted on this topic some time ago but am unable to view the post.
I am still occasionally experiencing  warbling tones instead of connection to the desired subscriber number when using 18185 or 1899 for daytime calls. Sometimes it affects only one of 18185 or 1899, sometimes both numbers. It seems to occur at random times.
The last time I posted about this nobody else reported the same problem but it is difficult to believe that I can be the only person subjected to this.
Can anybody explain what is happening?

Patrick1 wrote on Oct 16^th, 2007 at 11:58am:

Can anybody explain what is happening?

A finite number of customers can be using the service at any one time. What you're hearing is probably this limit has been reached.