'99 V70 XC getting worse...

[Avery]

My XC's 'ABS' and 'Brake' lights come on simultaneously. Then the speedometer drops from whatever speed I'm at right down to zero. All other gauges remain good. At this time the cruise control also drops out, until the 'ABS' and 'Brake' lights go out (usually within two minutes). Shortly after that, the speedo jumps back up to normal, and after that the cruise control resurrects itself.

Very occasionally there's a power loss from a standstill, like trying to pull out into traffic--the car just won't get out of its own way even with the accelerator way down. A few seconds later it picks up again.

AND...the hunting (at idle) that I asked about in November is still there, and worse (revs between 600 and 1200 when engine is warm).

The dealer replaced the speed sensor (I think) to no avail except a $500 bill. Any suggestions? Are any of these symptoms related to one another?

Thanks.