ok i need some advice.
one of the rooms i work in to do experiments has a rota etc for cleaning monitoring etc, which i always adhere to, however there is a girl/woman who freqeuntly 'complains' about me having gone in after me and made a mess, split things, then said to the manager of the room it was me to the extent now where he is threatening to revoke my permit!! i dont know what to do my supervisor is useless and blames me even though one of the days she complained i was not even in, its made me to upset as she never confronts me, and the only reason i can see for her being like this is once i asked her if she could hold off using the centrifuge while i finished an experiment. any advice on how to deal with this? my project depends on me being able to use the facility.

Very simple really, talk to her and if that doesn't work, then your sup.

if i understand correctly, she has repeatedly been blaming you for faults you never committed, and she has been blaming you for her own faults. and - as long as you don't confront her, she is getting away with it!
it sounds like you really need to turn things around. leave the defensive position of "i didn't do it". it obviously isn't convincing anyone - people probably find it hard to believe anyone would put up with someone repeatedly wrongly blaming you without saying anything but "it wasn't me" so they assume it probably WAS you. instead of waiting until she confronts you - that's what her whole play is built upon - YOU need to confront HER. she has been blaming you (for making a mess) plenty of times. now, for once you blame her (for wrongly accusing you). make it public. even if people then don't know who to believe - your position becomes more plausible than it is now, because you are actually doing something about it.

my sup rolls his eyes and says whatever when i say its not me. But think i will speak with her, but she is friends with them all which makes it harder!

I sympathise: it always seems like the real b*tches are really good at getting those in authority to believe them.

My advice would be to instigate - as an SOP - a system of signing a book or diary at the end of the day, stating that the machine has been switched off and cleaned up. Get a sup or technician to countersign. This is good lab practise anyway. Make a point of asking everyone to partake, that way a) it doesn't seem personal, and b) it makes a point that you are hardly likely to be making a big mess, if you are the one instigating an SOP for maintenance and cleaning.

You are allowed to do this; I've done it for maintenance of a mass spec.

thanks for the advice. i think some kind of book would be useful as i often leave earlier than her so at least if i sign off so to speak i cant be blamed!
i just cant understand people like this!

I really sympathise with you - I had a similar problem but never did anything proactive and ended up having a breakdown. That cost me nearly a year of productive work. My advice is do something official even if its just a well meaning email and make sure you cc your superviser or another academic in. That way you can be seen to be doing something positive

well today i found out there arranging a meeting to have me banned from the room despite me having tried to stand up for myself. so now im crying at my desk looking like a complete idiot and wondering if maybe i should just leave, if this is how the place works, what hope have i got of finishing my project.

God, PhDgirlie, what a nightmare! I would suggest that (if you can) you write down a log of everything - when you have used the lab and what has been said to you, etc

The supervisor dounds like s/he is just disinterested in the arguments rather than not believing you - to them it's just playground squabbles. However it's affecting your ability to work and that's the issue you need to carry forward. A university has a duty to provide research students with the equipment they need to carry out their work. IF your department intends to revok your permit just based on someone else's story without hearing yours, I would write a carefully worded letter to your director of research, and perhaps notify the postgrad stufdent union.

thanks thats really helpful i might ask for someone external from the uni to be present, im just so upset the situation has reached this stage. i am seriously ready to chuck it all in, as cant see how can progress like this!

Kronkodile's exactly right. I just wanted to query how official this "meeting" is: who are they having the meeting with?

my supervisor (who i have a poor relationship with - to quote him im a 'stupid and ditzy'.) the manager of the room, and if i choose human resources. I think i will just cry faced by them and know my sup wont support me at all.

Is this a small room (i.e. are you usually alone in there?) or are there other people who could perhaps be witnesses for you?

If you are not messy in other places where you work, then you are unlikely to be messy in this area: I would make that point. It does sound like her word against yours, and that should not be acceptable: everyone knows that people are sometimes vindictive. The onus is on her to prove that you are the problem (which she won't be able to do, of course).

ive been trying to think of a way to prove my point, going to speak with my other panel member who is friendly and ask her to maybe attend this 'meeting' as an impartial person.

your supervisor sounds exactly like mine! i would take it higher to be honest the institute where i work is like that, everyones willing to go behind peoples backs etc. can you speak to your Uni student advice group or anyone?