Worried about puss: fleas, foxes and behaviour

[lessonsintightropes]

Short story is that my cat seems to have got fleas. We have a family of five foxes in our (new-ish, lived here for a year) garden. I tried Frontline which didn't work, I gave it a week as there wasn't much evidence of the jumpy biters, but it then became obvious that we were getting infested - bitten in living room and dining room. I treated her with Advantage last night and used Indorex when I came in tonight which seems to have sorted things out. However, she didn't come to greet me when I came home from work which is highly unusual (very friendly Burmese mix) and despite living room window and back door open (both onto the garden) she has not come in at all, and is being standoffish.

She seemed to have settled here incredibly well despite our foxy friends - having been very tubby in our last flat which had very limited outdoor space, she has slowly slimmed down to a healthy size over 12 months, and she has been affectionate and lovely, her normal self. In a previous flat when she was being bullied by another flat she had been very nervy and peed a lot outside the box (this was years ago now) and I haven't seen any signs of that kind of stress.

She seems perfectly happy but unwilling to come into the house. Any ideas on what's going on?

[lessonsintightropes]

Edit: I am pretty sure she has caught them from the foxes as they are constantly scratching and nipping their fur. Any other ideas about making sure she stays flea free (other than regular indorexing of the house and advantage for her) would also be v v welcome.