@TM Back in the old days of BASIC (1980's) we needed to keep track of these DIMed variables and how they were placed on the stack. I remember winning a codeing competition because I placed my most frequently used variable first in the DIM statements. Variables were searched for starting at the first one defined (per subroutine) until found. If you placed the DIM statement for that variable at the end of all the DIM statements it took extra time to find it. Simply placing the most frequently used variable at the front allowed it to be found first and my code ran a lot faster.

Global Dimed variables might be the answer to this OP question but it looks like s/he needs to determine where the variable is defined and how/if it is being addressed in the code.