Big problem with excel recalculating spreadsheet

[Prometheus]

Background:
I work at a small water utility and I created a spreadsheet to track P&L. Basic stuff, compare water pumped to water sold to find loss, stuff like that. There are 2 times that the meter reading on a pump would be less than the previous reading. Either the meter rolled over or it was changed. To handle this, if the current reading is less than the previous I have a form open asking which situation it is and depending on user input it does one of 2 things. They recently added some new wells and I'm adding them to the spreadsheet.

Here is the problem:
When I add a new page excel recalculates the spreadsheet. What this means is, for every time that a meter rolled over or was replaced, the dialogue pops up again, so right now I'll get about 30 instances of the dialogue appearing. There is no indication of which meter the dialogue is for, so there's no way to answer correctly. I have set calculation to manual so that I could add the pages, but now when I set it back to automatic it still recalculates the entire spreadsheet. Leaving calculation on manual isn't an option because when I enter new data and force it to calculate the page it recalculates the whole page, and I get the dialogues again, with no indication as to which is being referred to. My question is, is there a way to force Excel to not recalculate the spreadsheet when I turn automatic calculation back on. Sorry if this is too much information, I wanted to be as specific as possible.

[robert111]

when you collect your meter readings, ask the inputter to enter reading AND a code
N = normal reading
R = rolled over
M = meter changed

then your spreadsheet could figure out for itself what reading to take

ie if code = R, reading = submitted reading + (10000000 - previous reading)
N submitted reading - prev reading
M you define the rules.......

[Prometheus]

That's actually a good idea and something that would have been awesome to implement when I made this thing (I had no idea what a pita it would turn out to be). Unfortunately this thing is huge now and there's no way I'd have time to make modifications like that. I've taken 1 semester of VB and had never touched excel before this so I've basically built the whole thing using trial and error with help I found on the net and these forums. Making substantial changes to the way it works would take me way more time than I have these days, it took me a good month of spare time at work to make it