i'm assuming the angel eyes are aftermarket? Its likely either the CCFL ballast or the connections to it. Try playing with the wires when they're not working, if they start its definatly a wiring issue.
mods please move this to e46 section.
hid lights hid kits
Hot: 2001 Estoril M Roadster
ZCP 19's, ZHP knob, JL 8W3
Cold: 2002 TiAg M3 6mt
ZCP 19's, ZHP knob, GROM, OEM 18's,