Asterisk audio dropouts

Hi everyone,

Im a bit of a newcomer to Asterisk, but I picking up lots as I go along. However, Ive got a problem which I cant overcome or even really locate the source.

Ive got a (borrowed) PC with a clone-X100P card. Im using the clone whilst I find whether Asterisk is something I wish to continue to learn about. The PC is a single procesor dual core with lots of memory but thats about all I know. Im also using a Linksys SPA3102 to connect my analog phone as a SIP extension.

The problem Ive encountered is that every so often on PSTN calls (both incomign and outgoing) the audio will drop for a second or two before coming back in. There is also quite a lot of echo but I think this may be due to the limitations of the cheap clone card.

Im happy to fork out for a more expensive digium card if I know that this will actually solve the problem and there isnt something else that could be causing this.

Ive made sure that the card is using its own interrupt by looking at /proc/interrupts but this hasnt helped. Ive found some references that seem to indicate that the dual core may cause a problem, but I cant find anythng definitive.

can anyone offer any other suggestions?