Hi.
I think tantalum bead capacitors are not to be trusted and agree that modern low leakage low ESR electrolytic capacitors generally make good replacements. I would have thought that tants are pretty safe in timing circuit applications where there's not a low impedance voltage source available to wreak havoc if the cap should fail short circuit.
It always gets me worried about working on live equipment that has tants connected across supply lines. Maybe they should be issued with a health warning to put on your eye protection!
Not just this, but the fire risk is very real.
Regards
Symon.