What exactly is an 'engine bleed problem', would this have been an unfortunate coincidence or ash related?
The air you breathe in any pressurised airliner (except the 787) is tapped off the engines downstream of the compressor and fed, via the air conditioning/environmental control system, into the cabin. It's not unknown for an engine oil seal to fail, which results in an intense smell (of burnt oil) and sometimes mist/smoke in the cabin.
The BAe 146 and Boeing 757 are, allegedly, more prone than most types to this kind of incident, in fact an Australian flight attendant on 146s has recently been awarded substantial damages against East-West Airlines for respiratory illness attributed to toxic fumes in cabin.