Topic: streetpass trouble - any help/advice?

well i just upgraded my 3ds to an xl and have copied all data across but now can't seem to streetpass my girlfriend have left both systems on for about 5 hours but no streetpass but i streetpassed my bro in like two minutes!when i first turned on the xl i set up a different user to streetpass my old 3ds and the misses but this was wiped when i did a system transfer, could this perhaps have left some random data packet in the system memory that could be blocking it? i doubt that because i gave my old 3ds to my bro and we streetpassed since. i can't find any help on the interwebs and thought i would ask the fine people on this site. without your help i can't venture forth!

i tend to find that spotpass is the usual culprit for not getting street passes from my friend when he comes round to my house. so we use that as an excuse to go for a walk to the local sweet shop, and get the pass at the same time.
you could also check through all the settings on your`s and your girlfreinds 3DS`, and whether the wireless mode has been switched on.
other than that, the only thing i can think of is whether the dates on your 3DS were not set right when you last streetpassed your girlfriend. if it comes up with "streetpassed 1 minute ago" you`ll need to figure out when the date was set and either wait untill you`ve gone passed that date, or keep changing your dates every time you see your girlfriend.

Update the system if you haven't already.

dizzy you are a genius,the clocks had got all messed up and it was throwing things out!!all sorted now guys, i really appreciate the help.And jumpman, you're right i am a lucky man 'cos i get a streetpass everyday and the pleasure of smashing her on mario tennis!!! XD lol i'll add you to my friend list if that's okay jumpman and the dreaming hawk?(i already have dizzy and you gentlemen should add him if he's not on your list already,thoroughly bloody nice bloke and wizard of stationary!) thanks again fella's, now it's time to VENTURE FORTH!!!

@cakeashi good too see you`ve sorted it out.
as for the stationery thing, you`ll have to thank everybody that i`ve added on my 3DS friends list (70 so far). i wouldn`t be able to pass them around if nobody shared them with me, hence the reason i ask everybody to share them around too.