Strange dip beam problem... Help??

[gumball3000]

The other day i removed my front bumper to mount my intercooler.. I then re-fitted the front bumper.. Later that night my dip-beam stoped working.. side lights, and high beam worked fine, and the dip beam light came up on the dash when i switched them on, but they were not working.

Then on my way home they just started working again, and have been working fine since.. Anyone know anything about this?? Could i have knocked an earth or something when removing the front bumper??

Any help appreciated to prevent it from happening again lol..

Thanks..