dog walking in circle's

I have a maltese, female, which we adopted about 3 years ago. She has always been very nervous around people and is very much a one family dog. She is very clingy and is very attached to me. If she is boarded she will not eat and even if she stays with family members she will not eat. We were out of town the last 4 days and she was able to stay at home because my mother stayed with my 13 year old while we were gone so she did eat for him (my son). When we returned home however we noticed that she cannot walk straight, she walks in circles only to the left. If she wants to get some where in a straight line she must walk with her body up against the wall and her head touching the wall. If she moves away from the wall or what ever she is against she starts going in circles again. I have asked my son if she hurt herself in any way while we were gone and he said no.
Any idea what is wrong with her? She is eating and doing everything normal except she can't stop the circling.

Any advice is greatly appreciated.

Thanks

Yikes. Almost sounds like some neurological problem...how is her hearing? Her eyesight? That's bizarre..I know that animals who have seizures can exhibit odd behaviour like that, but usually only during a seizure. The only other thing I can think of is an ear infection, but she would be shaking her head and scratching her ears. Ear infections can throw off their balance, though. See if her ears smell funky.

I'd say she's due for a vet visit...do let us know what your vet says!

She is fine now. Walking normal, eating very well and not turning circles any longer. I think a vet visit is in order though, for some medication for her neurotic behavior. It seems that she is so distraught when I leave her that she cannot function. My mother said that she paced and paced when I was gone. Even when I leave for work she is terrified, she starts shaking and will not stop. I put her outside with our other dog with food and shelter and she seems to like that much better than staying in our laundry room. (she is not housebroken 100%)
When I adopted her I was told that she was 4 yrs old and may have been abused. She has no teeth so she is a special needs child to begin with.