Spanish mobiles (Vodafone) in Gibraltar

Can anyone in the south of Spain, advise if Spanish mobiles work in Gib.

I know they will probably work roaming, but do they work still on the Spanish system seeing as the border is close where ever you are in Gib.

I have a Spanish mobile on Vodafone and I'm in Gib most days .... there coverage is really bad - I can't get anything on Main Street or Irish Town. If I'm near Morrisons I may be able to get a signal on vodafone.
The phone will roam to gibtel, but I can't make or receive calls from gibtel so it's pretty pointless really!

Thanks for the reply, only there for a short time so will make do.