B and C semileptonic decays in OPAL

For several years, experimental results for BR(b to lX) obtained near the Upsilon (4S) and Z/sup 0/ resonances have disagreed at the few sigma level. A new OPAL result for BR(b to mu X) based on the full data sample collected near $9 the Z/sup 0/ resonance is presented here. The result is extracted using muon momentum and jet shape information in b-tagged events. The inclusive charm hadron semileptonic branching ratio is measured in a charm enriched sample of $9 hadronic Z/sup 0/ decays. New analysis methods used by OPAL to extract (b to mu ) and (c to l) are discussed in more detail, and the OPAL results are compared to those from other experiments. Both results are preliminary. (11 refs).