how can know if my site is sandboxed

so here is the story
i have a site that i get a retainer to do seo for, it is low competition for the keywords and not many searchs so it was easy to get in up to first place on google but i got very little on msn and yahoo which at the time was ok
i noticed latliy that it was driffting back and losing grount slliping away from first place it is a site a few months old so i did not see a problom with using x rumer on it i fired out some 15,000 links but although i saw the webpage go from 3440 links on the google search for the webpage to 5650 i did not see it move up...and it is not to be found with a search on the key words also i did not see any google links are yahoo bing alexa or any pr assiend to it.. for fair disclosure i did change and update and fine tone the keywords but since its low competition so i dont see how it can not be found ...and no links are presented with SEOquake even though it does have 5000 and more links in a reguler website google search any suggestion? am i sandboxed? the site address is
http://www.rabbishlomocarlebach.com
please advise wizards
thanks

You are definitely not sandboxed - you come up on the first page for תיירות מבוא מודיעים as well as "Carlebach Moshav" You may be dropping due to technical issues on the site - its not optimal HTML and you should probably pay close attention to language attributes (charset=ISO-8859-1 ?? need to consider using some lang attributes)