Calculations Slow

Ok I am all out of ideas. I have a data table that is about 30000 lines. My sheet plugs in information so people don't have to type it. The calculations are slowing way down since I extended the table so large. I expected that, but I have tried to change the calculations to manual, automatic, semiautomatic in my macros that I have created. Each column on my sheet has a toggle button at the top so the people can sort the information up and down. When I use those buttons now since the table is so big you can see the blue coming across the screen like a wave. When I tried changing the caluculations in these togglebuttons, they worked sometimes and sometimes they didn't. I also tried to speed it up by turning the screenupdating on and off in the scripts and this made my toggles worse, they would work one way and not the other. So do you have any ideas I am out of them. I'll put examples of my sheet formulas and a script on so it can be seen.
Thanks in advance for the help,
Bob

Sub Macroc1()


Rows("4:250").Select
Selection.Sort Key1:=Range("u4"), Order1:=xlDescending, Key2:=Range("c4") _
, Order2:=xlAscending, Key3:=Range("D4"), Order3:=xlAscending, Header:= _
xlGuess, OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom, _
DataOption1:=xlSortNormal, DataOption2:=xlSortTextAsNumbers, DataOption3 _
:=xlSortNormal
Range("c4").Select

End Sub



=IF((AND(E4="")),"",(IF(ISERROR(VLOOKUP(E4,'Component Table'!$A$1:$L$50000,4,FALSE)),"Description Not Available",VLOOKUP(E4,'Component Table'!$A$1:$L$32000,4,FALSE))))

The main files are all on the server, but even ehen I work on the files or update them I copy the file to my hard drive and work from there then do my updates when i am sure everything is working properly to the hard drive and they are just as slow no matter where they are.
Thanks for your input though,
Bob