question on DSL signal

[Wojciech Puchar]

> without a single drop, while other times it's up for 30 seconds,
> down for a minute, up for 2 minutes, down for 1.  That can go on
> for 10 hours, and then maybe it's stable again for a day or so.
> It's always appears to be the DSL signal itself, as I can see the
> modem sync light starts flashing when the signal goes down.

make sure you don't get a timeout because of high load or simply - the 
server you ping doesn't respond.

> To end any possibility of the phone company pointing their finger
> at the wiring in my house, I put the DSL modem right at the phone
> connection block where the line enters the house and then called
> them. Problem persists.

looks like polish telecom isn't anyway  special ;)

> "found the problem", but when he's gone, the trouble starts again.

it's not line problem but modem hardware problem or their routing problem.