jQuery Grid Plugin - jqGrid

Chrom / Safari have problem displaying grid:

Error:

Uncaught TypeError: Cannot read property 'display' of undefined

Problem seems kind of releated to this older thread(solved):

/uncaught-typeerror-cannot-read-property-classname-of-undefined/

1. modal-search does not appear properly

• some fields have style="display: none"

• By hitting "search", the data loads successfully with ajax in the background but the screen does not respond. 

• no button does responde without modifiying code with firebug

2. The Navigation-toolbar has some issues

• the "page x of y". the "x" is always 0.

• after changing selbox (number of rows per page) the data does not get loaded onchange.

In IE & Firefox it works … only Safari & Chrome make problem. Css is taken from jquery  ui 1.8.10, it should not be a css-issue because why are some div's hidden in chrome and safari only?

Thanks for your participation,

Kind regards