jQuery Grid Plugin - jqGrid

that page number box is crazy big. have you done any other alterations to the CSS ?  If you use a debugger/DOM explorer (like chrome tools or firebug) are you able to see those elements affected by any other CSS you may have on the page ?

Is there an example available for us to see of this behavior ?

is this on a public-facing website by chance that we can look at ?

Otherwise, its a little hard to explain.  You basically right click the element you want to look at (such as the paging box) and say Inspect Element.  Then you should be able to see the stylesheets that are applied to the element in the development console. Try to figure out which stylesheet is affecting the paging box to stretch it so wide. 

You can also make sure the element itself hasn't been modified. For example, the box should have html attributes like this

so the text box should have size=2.  You can look at the computed styles to see if there is anything which is modifying the width of the element. 

the order in which your css files are included does play a role.  whichever file is included LAST in the page has highest precedence.  So you can try moving the jquery-ui CSS and jqgrid CSS down below the web2py.css to see if that helps.  Unfortunetly, unless the jquery-ui or jqgrid css explicitly set the width on input elements, the web2py.css is still going to be applied. 

Of course you could also pull out the web2py.css entirely if it is not included in the page.  Having such a generic selector in that file is likely going to cause problems elsewhere as well. Its possible that there are some styles in that stylesheet which are affecting other elements like the dropdown you mentioned in your original post.   If you comment out that stylesheet does everything look as expected ?