No common problems as far as I'm aware.
Be worthwhile putting it over a pit/on a ramp and see if you can spot where it's leaking.
Make sure you check the visible hoses first though, the ones you can get to from the top of the bay. Also the seals around the pump
2001 Milano Red , Eibach springs, VtecDirect Mani, downpipe, decat and zorst, ported and polished head, K+N panel filter, VtecDirect oil cooler, lightweight pullies, XTD lightweight flywheel, Full new set of valves retainers and springs, DS250 pads, Bremtech disks, throttle body coolant bypass, New standard ATR cams and a re-built head, balance belt removed, Volk TE37 - resprayed in Anthracite. Light Tints, K+N Long Ram Typhoon.
1997 Impreza 555 RA - New Cosworth forged pistons and matching piston rings *.50 oversize.**Rebore block to suit New Crankshaft. New race quality crank bearing set. APi uprated oil pump.STi 2003 year model con rods.STi gasket and seal set, baffeled sump.* Stage 2 organic clutch, lightweight competition spec. Flywheel and balance, TD05G20 Turbo, Standalone ECU, 650cc injectors. HDi Hybrid racing front mount intercooler.