That sort of thing has happened to me many times while using FreeBASIC. A few years ago the FB compiler was still young and had a myriad of bugs lurking in corn

That sort of thing has happened to me many times while using FreeBASIC. A few years ago the FB compiler was still young and had a myriad of bugs lurking in corner cases; I've encountered dozens of compiler crashes, strange interactions between unrelated bits of code that produced nonsensical error messages and fixed by rearranging, parsing and lexing bugs, including the lexer accepting the most remarkably garbled input, especially when I tried writing a PEG grammar for FB. Also, the preprocessor is pretty nice - looks like C's but with vastly better semantics, and if you find a bug in it, you can exploit it for even more advanced constructs! :) Like how // in early C behaved like the non-existent-at-the-time ## operator. 'STRANGE: For some reason I have to add a comment here or FreeBasic 0.24-pre doesn't compile it I've even seen what donatj said, of changing the source and then changing it back in order to remove an error. That sort of thing is generally a problem with the build system not producing reproducible results, such as not files not being recompiled when necessary. Since I have my own DSL that spits out FB code, and the FB code produced in different modules can have hidden conflicts, I've actually seen that one multiple times (my own fault). Really, the amazing thing is that just a few years later FB is actually pretty stable. I don't mean to put it down; I'm quite impressed with their work.