Mark, I think you just have to watch where you lay them down. Quite a few area's are marked in like zones with the beds and umbrellas.
We have laid ours down at the back away from the beds without any trouble in both SB and GS.

Toonman

ok thanks for that.

Will have to look and see when I get there

We were there last week and there was a rope in the sand which you could sit on towels in front of. However, there was a really rough sea and the rope disappeared under the sea so there wasn't anywhere to sit in the dry!

Two sunbeds and a brolly cost about 25 leva. Unfortunately the price stays the same whether you are there for 5 mins or 5 hours... Apparently the beds are run by the council or something.

Maz