naming conventions for linux server

My site was moved in godaddy.com from the windows server to the linus server so that I could us php for form email - send without a "mailto" and pull up a new page once the form is submitted. I am using dreamweaver with SpryAssets, framework/mootools.js and some additional client-side javascript Now, my site, which worked perfectly on the windows server is "broken" because, according to the tech staff at godaddy, of coding issues... Can some out there please identify for me what I should look for? For example, -- do file names have to all lower case? -- Are there restrictions on what can be in a filename such as symbols, numbers, etc. -- is there some restrictions on how to call a file? Any help would be appreciated. Thank you, in advance, for your time.

Thank you. Another question. A vanilla file, just using <p> to format form fields will find the referrer file, however, the same form in a table formated with <table>,<tr>,<td>,  , font info, etc. will not. Does Linus have a problem/limitations/preferences with table and formatting codes.