Asterisk dialing on PSTN generates incorrect tones

G’day all,

latest Asterisk and zaptel 1.4 from SVN on amd64

I am having a weird problem, all out going calls suddenly returned the telco’s unavailable message and while listenting with zapscan the dialtones are sounding very weird not the standard frequencies at all.
All the country settings seem to be correct …
Any suggestions about what could be wrong?